问题：
[单选题] NAC's（Network Access Control）role is to restrict network access to only compliant endpoints and（ ）users.However,NAC is not a complete LAN（ ）solution;additional proactive and（ ）security measures must b
A、defense
B、intrusion
C、inbreak
D、protection
参考答案：
A、defense
● 参考解析
