A company has a Frame Relay WAN with one central - site router and 100 branch office routers. A partial mesh of PVCs exists: one PVC between the central site and each of t he 100 branch routers. All routers use point - to - point subinterfaces and one subnet per PVC. Which of the following is true about OSPF in this design?（）

• A、The central site router has 100 fully adjacent neighborships with the 100 branches
• B、The central  site router has neighborships with all branch routers, but fully adjacent neighbors with only two branches
• C、The central site router has a neighborship with the Frame Relay switcH
• D、None of the other answers is correct