Refer to the exhibit.

Switch 1 and switch 2 run open Shortest Path First (OSPF) on all VLANs. Both switches establish an OSPF adjacency to a router at the main data center. Exhibit shows shoes some virtual Routing Redundancy Protocol (VRRP) and OSPF settings on Switch 1 during normal operation.
How can a network administrator increase the resiliency of this solution?
Correct Answer: D
Explanation/Reference:
Today many Internet routers implement a separation of control and forwarding functions. Certain processors are dedicated to control and management tasks such as OSPF routing, while other processors perform the data forwarding tasks. This separation creates the possibility of maintaining a router's data forwarding capability while the router's control software is restarted/reloaded. We call such a possibility
"graceful restart" or "non-stop forwarding".
Reference: RFC 3623, Graceful OSPF Restart
https://tools.ietf.org/html/rfc3623