Under the MAC control system, what is required?

A.
Performance monitoring

B.
Labeling

C.
Sensing

D.
None of the choices

Explanation:
It is important to note that mandatory controls are prohibitive (i.e., all that is not
expressly permitted is forbidden), not permissive. Only within that context do
discretionary controls operate, prohibiting still more access with the same
exclusionary principle. In this type of control system decisions are based on privilege
(clearance) of subject (user) and sensitivity (classification) of object (file). It
requires labeling.