Final answer:
The time taken for the desired sector to rotate to the disk head is called rotational latency.
Step-by-step explanation:
The correct answer is d) rotational latency. The rotational latency refers to the time it takes for the desired sector to rotate to the disk head. This is the time delay that occurs before the data can be accessed or read from the disk. It is an important factor in determining the overall performance of a disk drive.