A company is looking to donate a collection of old PCs that are no longer needed. Which of the
following data destruction methods would be MOST secure for highly sensitive information?

A.
Simple 1-pass zero overwrite

B.
Low level 3-pass random wipe

C.
Low level 7-pass random wipe

D.
High level format 10 times

Explanation:
http://superuser.com/questions/215852/is-using-multiple-passes-for-wiping-a-diskreally-necessary