Using an operating system and file management

The governing concept is access control in encryption. An encrypted file is designed to remain unreadable without the required password, key, or approved recovery method. Consequently, forgetting the password can prevent the rightful user from opening the contents; it does not make the file public or affect the monitor and printer. A recovery key or secure password record may reduce this risk. Therefore, option C is correct.

The governing concept is safe file handling. A filename and extension are labels supplied by a user or program and may be misleading; a harmful executable can be given a familiar or attractive name. Checking the download source, digital signature, reputation, and security scan provides stronger evidence, although no single check is perfect. Therefore, option D is correct.

The governing concept is authenticity and integrity. A valid digital signature can help identify the claimed publisher and show whether signed file contents were altered after signing. It does not change the file’s appearance, increase RAM, or compress data. A signature is useful evidence, but users should still consider source reputation and scan for threats because a valid publisher does not make every file harmless. Thus, option A is correct.

The governing concept is integrity verification using a digest. A hash function produces a value derived from a file’s contents; even a small change will normally produce a different value. Comparing a downloaded file’s hash with an official value can therefore reveal corruption or alteration. A hash does not print, transfer ownership, or lock the computer, and it is not a replacement for encryption. Option B is correct.

The governing concept is integrity checking before execution. A hash mismatch means the downloaded bytes differ from the official reference; this may result from corruption, an incomplete transfer, or unauthorised modification. The safest response is not to open or distribute the file, to remove or isolate it, and to obtain a fresh copy from a trusted source before checking again. Renaming cannot repair its contents, so option C is correct.

The governing concept is synchronisation between copies. A synchronisation process compares changes and attempts to keep corresponding files updated across two or more locations, such as a computer and approved cloud storage. It is different from a one-time copy because later edits may also be propagated. It does not delete files, make them read-only, or control display brightness. Therefore, option A is correct.

The governing concept is version control in synchronisation. If two devices edit the same file before their changes are merged, the service may find incompatible revisions and report a version conflict. The user may then need to compare versions and choose or combine the correct content. Deletion, monitor resizing, and device shutdown are not normal results of simultaneous editing, so options A, C, and D are unsuitable.

The governing concept is propagation of file actions through cloud synchronisation. When a file is deleted inside a synchronised folder, the service may transmit that deletion to the cloud and to other connected devices. This can cause unintended data loss, although a recycle bin, version history, or recovery facility may sometimes help. The action does not merely hide the file, change its extension, or increase RAM.

The governing distinction is purpose. Synchronisation attempts to keep connected locations in the same current state, so an unwanted edit or deletion can also spread. Backup is intended for recovery and may retain an earlier copy, depending on its retention settings. Therefore option D correctly separates the two functions; the other choices describe neither service accurately.

The governing concept is the relationship between storage space and operating-system operation. The system needs free disk space for temporary files, caches, logs, paging, and downloaded updates. If space becomes very low, updates may fail and overall performance or stability may suffer. Monitor size, printer-ink quantity, and mouse connectivity are unrelated to available disk capacity, so B, C, and D are incorrect.

The governing concept is cautious storage maintenance. A disk-cleanup tool usually presents categories such as temporary files, caches, or recycled items, but the user should review what is selected and confirm that no needed document, installation file, or recovery data is included. Option B follows this safe process. Deleting personal files, the operating-system folder, or every backup is unnecessarily destructive.

The governing concept is safe deletion. Although many temporary files can be removed, some may still support an open application, an unfinished operation, an installation, or a recovery process. The user should close relevant programs and check the file category before deleting it. Option C expresses this necessary check; monitor colour, mouse size, and printer ink have no bearing on temporary-file safety.

The governing concept is safe handling of potentially malicious files. A suspicious preview may indicate an unsafe source, misleading extension, or harmful content, so opening or distributing the file could expose the device or others. The safest next step is to avoid opening it, verify who supplied it, and use an appropriate security scan. Hiding the extension does not remove the risk, making D correct.

The governing concept is systematic troubleshooting. First define the symptom, then examine simple causes such as the file path, access permissions, file format, and application association. After making a suitable correction, test the file again and verify the result. Option A follows a controlled sequence. Permanent deletion, operating-system reinstallation, and deleting backups are extreme actions that may destroy evidence or data without identifying the cause.

The governing concept is layered file-management safety. Good practice combines clear folders and names, least-necessary permissions, regular and recoverable backups, trustworthy sources, and proper shutdown or closing procedures. No single habit is sufficient by itself. Option B combines prevention, organisation, security, and recovery, whereas short names or a crowded desktop do not ensure safety, and opening unknown files increases risk.

The governing concept is a shortcut’s stored target reference. A shortcut usually records the location and name of the file it should open; renaming or moving that target can make the stored reference invalid. Updating the shortcut or selecting the renamed file can repair the link. RAM capacity, monitor resolution, and automatic compression do not normally explain this specific failure, so option A is correct.

The governing concept is file access permission. Read permission allows a user to open and view the contents, while write permission is needed to modify and save changes. Therefore, option B is correct: the user can view the file but cannot normally save edits to it. Renaming, deleting, or changing permissions generally requires additional write, delete, or administrative rights, so options A, C, and D are not guaranteed.

The governing concept is concurrent editing of a shared file. When two users save different changes at nearly the same time, one version may replace part or all of the other, creating a version conflict or lost update. Option C correctly describes this risk. A shared edit does not normally make the file size zero, shut down the operating system, or alter the monitor colour, so A, B, and D are irrelevant distractors.

The governing backup principle is independence of storage locations. A second folder on the same physical drive is only another copy, not protection against failure of that drive. If the drive is damaged, lost, or becomes unreadable, both the original and the copy may disappear together. Thus option D is correct. Renaming, hiding, or automatically doubling the file size is not the main consequence, so A, B, and C are distractors.

The governing concept is search scope and file visibility. A search can fail because it is limited to the wrong drive or folder, excludes hidden items, or applies an unsuitable filter. Therefore, option A is the best next step: inspect other drives, enable appropriate visibility, and confirm the search location. Formatting the computer or deleting folders could destroy data, while replacing the monitor cannot improve file search results.

The governing concept is avoiding accidental overwriting. An existing-name warning indicates that saving with the same name may replace or alter the earlier file. Option B is safest because the user first compares the files and then chooses a new name, keeps both versions, or deliberately confirms an overwrite when appropriate. Overwriting without reading may cause data loss; shutting down or emptying the Recycle Bin does not resolve the naming conflict.

The governing security concept is identifying a file by its complete name and extension. An extension such as .exe, .bat, or another executable type can reveal how a file may behave. If extensions are hidden, a harmful file can be made to look like an ordinary document, increasing the chance of unsafe opening. Option C is correct. Hiding an extension does not increase file size, move the folder, or slow the monitor.

The governing concept is permanent deletion and recovery. A normal delete often moves a file to the Recycle Bin, but permanent deletion bypasses that convenient restore location. If no verified backup exists, the data may be lost and cannot normally be recovered through the usual Restore command. Thus option D is correct. Changing colour, system time, or RAM usage is not the expected result of deleting one file.

The governing concept is the two-stage copy process: data is read from the source and written to the destination. If the source drive disconnects before the transfer finishes, the destination may contain only part of the data or a corrupted file. Therefore, option A is correct. Copying normally does not delete the source, change its extension, or create a complete older-version file automatically, so B, C, and D are unsuitable.

The governing concept is safe removal of removable storage. A busy message can mean that a file is still being written, read, or held open by an application. The safest action is option B: close the relevant program and wait until the active process finishes and the system confirms removal. Pulling the drive out or cutting power during writing can corrupt files. Formatting is unnecessary and would erase data rather than solve the busy status.