In a client-server system, which of the following control techniques is used to inspect activity from known or
unknown users?

A.
Diskless workstations

B.
Data encryption techniques

C.
Network monitoring devices

D.
Authentication systems

Explanation:
Network monitoring devices may be used to inspect activities from known or unknown users and can identify
client addresses, which may assist in finding evidence of unauthorized access. This serves as a detective
control. Diskless workstations prevent access control software from being bypassed. Data encryption
techniques can help protect sensitive or propriety data from unauthorized access, thereby serving as a
preventive control. Authentication systems may provide environment wide, logical facilities that can differentiate
among users, before providing access to systems.