Refer to the exhibit. Routers R1 and R2 are directly connected through a FastEthernet link but cannot form a neighbor adjacency. What could resolve the problem?

The cost on R1 should be set higher.
The priority on R1 should be set higher.
The OSPF process ID numbers must match.
A backup designated router needs to be added to the network.
The hello and dead timers must be configured with the same values on both routers.