Which of the following is NOT appropriate in addressing object reuse?

A.
Degaussing magnetic tapes when they’re no longer needed.

B.
Deleting files on disk before reusing the space.

C.
Clearing memory blocks before they are allocated to a program or data.

D.
Clearing buffered pages, documents, or screens from the local memory of a terminal or printer.

Explanation:
Object reuse requirements, applying to systems rated TCSEC C2 and above, are used to protect files, memory,
and other objects in a trusted system from being accidentally accessed by users who are not authorized to
access them.
Deleting files on disk before reusing the space does not meet this requirement and is therefore not appropriate
in addressing object reuse.
Deleting files on disk merely erases file headers in a directory structure. It does not clear data from the disk
surface, thus making files still recoverable. All other options involve clearing used space, preventing any
unauthorized access.
Incorrect Answers:
A: Degaussing magnetic tapes when they’re no longer needed protects files from unauthorized access by
destroying the data on the tapes. This is a valid method of addressing object reuse.
C: Clearing memory blocks before they are allocated to a program or data removes any residual data from the
memory thus preventing unauthorized access. This is a valid method of addressing object reuse.
D: Clearing buffered pages, documents, or screens from the local memory of a terminal or printer removes any
residual data from the memory thus preventing unauthorized access. This is a valid method of addressing
object reuse.