If a fast processor repeatedly waits for data from a slow hard disk, which component is the bottleneck?

Correct answer: The hard disk

The bottleneck is the component that limits the flow of work. Here, the hard disk supplies data more slowly than the processor can use it, so the processor remains idle while waiting. Therefore option A is correct. The monitor, keyboard, and speaker may participate in input or output, but none is identified as the limiting data-storage component in this situation.