This question is about the formation of OSPF adjacency. An OSPF adjacency will not form correctly across a point-to-point link in the same area. Which would most likely cause this problem？（）

• A、Each interface has a different OSPF cost.
• B、Each interface is configured with secondary addresses as well as primary addresses.
• C、Each interface has a different MTU size.
• D、Each interface is configured with theip unnumbered loopback 0 command.