下面无人值守系统中DHCP服务器参数配置正确的是:A.subnet 192.168.2.0 netmask 255.255.255.0 { default-lease-time 600; max-lease-time 7200; range 192.168.2.100 192.168.2.150; }B.subnet 192.168.2.0 netmask 255.255.255.0 { default-lease-time 600; max-lease-time 7200; range 192.168.2.100 192.168....