Which software is useful for typing a letter or paragraph?

Correct answer: Word processor

The governing concept is document creation using application software. A word processor is designed to enter, edit, format, save, and print letters and paragraphs, so option B is correct. A media player handles audio or video, antivirus software detects and helps block malicious software, and spreadsheet software organises data in cells and supports calculations. Thus the writing task clearly points to a word processor.