what is the cause of this problem?

A network administrator is troubleshooting the OSPF configuration of routers R1 and R2. The routers cannot establish an adjacency relationship on their common Ethernet link. The graphic shows the output of the show ip ospf interface e0 command for routers R1 and R2. Based on the information in the graphic, what is the cause of this problem?

A.
The OSPF area is not configured properly.

B.
The priority on R1 should be set higher.

C.
The cost on R1 should be set higher.

D.
The hello and dead timers are not configured properly.

E.
A backup designated router needs to be added to the network.

F.
The OSPF process ID numbers must match.

Explanation:
Certain parameters within the OSPF hellos must match in order for two routers to become neighbors. They include:
1 Hello/dead timers
2 Area ID
3 Authentication type and password
4 Stub area flag
Hello and dead intervals are not same on both routers.