A . route add–net 192.168.1.0 gw 192.168.1.1netmask 255.255.255.0metric1
B . route add–net 172.16.1.0 gw 192.168.1.1netmask 255.255.255.255metric1
C . route add–net 172.16.1.0 gw 172.16.1.1netmask 255.255.255.0metric1
D . route adddefault 192.168.1.0 netmask 172.168.1.1metric1