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

A. The hello/dead timer does not match.
B. The link is a point-to-point connection.
C. The process IDs do not match.
D. The area IDs do not match.

A. In order to form an adjacency, the area IDs must match as well as the hello and dead timers. If the hello timer is changed on one router, it must be changed on the other router to form an adjacency.