Which two of the following actions must an OSPF NSF-capable router execute after a supervisor engine switchover?

Which two of the following actions must an OSPF NSF-capable router execute after a supervisor engine switchover? (Choose two.)

A.
Re-learn the available OSPF neighbors with neighbor relationship restart

B.
Send the graceful restart message

C.
Re-acquire the link state database content for the network

D.
Re-learn the available OSPF neighbors without neighbor relationship restart