You are the security practitioner for your company. The company has recently adopted a new asset disposal policy in which you are required to render any information stored on magnetic media unrecoverable by forensics methods. Which of the following should you use?

A. Data clearing
B. Remanence
C. Formatting
D. Data purging

D
Explanation: You should use data purging, which uses a method such as degaussing to make the old data unavailable even with forensics. Purging renders information unrecoverable against laboratory attacks (forensics).
Data clearing renders information unrecoverable by a keyboard. This attack extracts information from data storage media by executing software utilities, keystrokes, or other system resource executed from a keyboard.
Remanence is any data left after the media has been erased. Formatting only removes the reference to the data and allows overwriting of the data, but does not completely erase the data.