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.