Final answer:
Defragmentation is the process of rearranging files on a hard drive to improve a computer's efficiency, primarily by organizing data in contiguous sections to reduce read/write head movement for HDDs.
Step-by-step explanation:
The term that describes the process of rearranging files on a hard drive to make the computer run more efficiently is A) Defragmentation. When you defragment a hard drive, the computer reorganizes the data so that files are stored in contiguous sections. This minimizes the amount of movement the hard drive must make to access data, which can speed up your computer considerably.
Defragmentation is particularly useful for mechanical hard disk drives (HDDs), where the physical movement of the read/write head over the spinning disks can result in significant latency when accessing fragmented files. However, it is less relevant for solid-state drives (SSDs) where there is no physical movement involved in data reading and writing. Nonetheless, modern operating systems often include utilities to defragment a hard drive as part of regular maintenance to keep the computer running smoothly.