Hard Disk Drives Have Self-Parking Heads That

Hard disk drives have self-parking heads that

A) Use software to make the heads pull away from the data area and park in a safe zone on the platter
B) Make the hard disk drive safe from any jolts and jarring vibrations
C) Automatically lock the heads in place away from the area where data is stored when the computer is turned off
D) Allow the hard disk to be disassembled and reassembled without the fear of losing data