Refer to the exhibit. Routers A and B are directly connected and running OSPF， but they are unable to form a neighbor relationship. What is the most likely cause？（）
- A The routers are not on the same network.
- B The network statements do not match.
- C The process number does not match.
- D The MTU does not match.
- E The OSPF cost does not match.
- F There is a physical issue with the cable.