题目内容：
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 be implemented,Nevis is the first and only comprehensive LAN security solution that combines deep security processing of every packet at 10Gbps,ensuring a high level of security plus application availability and performance.Nevis integrates NAC as the first line of LAN security（请作答此空）.In addition to NAC,enterprises need to implement role-based network access control as well as critical proactive security measures—real-time,multilevel（ ）inspection and microsecond threat containment.
A.defense]
B.intrusion
C.inbreak
D.protection
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