The security functionality defines the expected activities of a security mechanism, and assurance defines

A.
The controls the security mechanism will enforce

B.
The data classification after the security mechanism has been implemented

C.
The confidence of the security the mechanism is providing

D.
The cost/benefit relationship

Explanation:
C: The functionality describes how a mechanism will work and behave. This may have nothing to do with the actual protection it provides. Assurance is the level of confidence in the protection level a mechanism will provide.When systems and mechanisms are evaluated, their functionality and assurance should be examined and tested individually