Which Item Is the Primary Requirement When Deploying OSPF Graceful

Multiple Choice

Which item is the primary requirement when deploying OSPF graceful restart on a router?

A) Some form of fast Layer 2 down detection must be enabled on the router.
B) The adjacent router must support graceful restart helper mode.
C) The adjacent routers must be enabled to forward traffic during the failure.
D) Aggressive routing protocol hellos and keepalives must be running on the router.