【单选题】What is the most important of the realities listed?
A.
New vulnerabilities will be introduced into your environment every day.
B.
If employees disregard warnings about the hazards of opening questionable email attachments, the manager should educate them about properly configuring firewalls and intrusion detection systems for their PCs.
C.
Managers have more responsibility than ever.
D.
Security managers are asked to support increasing degrees of network availability and access.