单项选择题

A.添加路由:route add-net 192.168.1.0netmask 255.255.255.0gw 192.168.1.1
B.删除路由:route del-net 192.168.1.0
C.添加默认网关:route add default gw 192.168.120.240
D.添加路由:route add-net 192.168.1.0/24dev eth0