Refer to the exhibit. The interfaces of all routers are configured for OSPF area 0. R3 can ping R1, but the two routers are unable to establish a neighbor adjacency. What should the network administrator do to troubleshoot this problem?

Refer to the exhibit. The interfaces of all routers are configured for OSPF area 0. R3 can ping R1, but the two routers are unable to establish a neighbor adjacency. What should the network administrator do to troubleshoot this problem?


Check if the interfaces of the routers are enabled.
Check the hello and dead intervals between the routers.
Check the process ID of both routers.
Check if CDP is enabled on all the routers.