NAC，s rNetwork Access Control)role is to restrict network access to only compliant endpoints and (71) users．However，NAC is not a complete LAN (72) solution；additional proactive and (73) security measures must be implemented．Nevis is the first and only comprehensive LAN security solution thatcombines deeD security processing of every packet at 10Gbps，ensuring a high level of security plus applicationavailability and Derformance．Nevis integrates NAC as the first line of LAN security (74) ．In addition toNAC．enterFIrises need to implement role．based network access control as critical proactive security measuresreal．time，multilevel (75) inspection and microsecond threat containment

A．constructive
B．reductive
C．reactive
D．productive

有三只电压表，现欲测量30V电压，要求误差最小，则使用（）表最优。

A、500V，0.2级

B、100V，1.0级

C、50V，1.5级