Which command do you enter to enable authentication for OSPF on an interface?

Which command do you enter to enable authentication for OSPF on an interface?
A . router(config-if)#ip ospf message-digest-key 1 md5 CISCOPASS
B . router(config-router)#area 0 authentication message-digest
C . router(config-router)#ip ospf authentication-key CISCOPASS
D . router(config-if)#ip ospf authentication message-digest

View Answer

Answer: A