In the following exhibit, Router A will not form an adjacency with Router B. What is the problem?

A. The routers are not in the same network.
B. The routers have mismatched process IDs.
C. The routers have passive interfaces.
D. The hello/dead interval is wrong for serial links.

C. Both routers have passive interfaces for OSPF. In order to fix this, the command no passive-interface serial 0/0 would need to be entered. This command would need to be configured in the OSPF router process.