A device that generates coercive magnetic force for the purpose of reducing magnetic flux density to zero on media is called:

A.
Magnetic saturation

B.
Magnetic field

C.
Physical destruction

D.
Degausser

Explanation:
A degausser is a device that generates a magnetic field (coercive
magnetic force) so that it changes the orientation of the bits held on the media
(reducing magnetic flux density to zero).