Which command on PE-B successfully completes the configuration?

Refer to the exhibit:

An engineer wants to authenticate the OSPF neighbor between PEA and PE-B using MD5.

Which command on PE-B successfully completes the configuration?
A . PE-B(config-if)#ip ospf message-digest-key 1 md5 44578611
PE-B(config-if)#ip ospf authentication message-digest
B . PE-B(config-if)#ip ospf message-digest-key 1 md5 44568611
PE-B(config-if)#ip ospf authentication null
C . PE-B(config-if)#ip ospf message-digest-key 1 md5 44578611
PE-B(config-if)#ip ospf authentication null
D . PE-B(config-if)#ip ospf message-digest-key 1 md5 44578611
PE-B(config-if)#ip ospf authentication key-chain 44578611

View Answer

Answer: A