An administrator types in the command router ospf 1and receives the error message:
“OSPF process 1 cannot start.” (Output is omitted.)
What should be done to correctly set up OSPF? Select the best response.

A.
Ensure that an interface has been configured with an IP address.

B.
Ensure that an interface has been configured with an IP address and is up.

C.
Ensure that IP classless is enabled.

D.
Ensure that the interfaces can ping their directly connected neighbors.

Explanation:
OSPF can be only started when there is at least oneinterface up and configured with an IP
address on the router.