The OSPF External LSA for prefix x.x.x.x exists in the OSPF database， but the prefix is not installed in therouting table. Which are possible explanations？（）

• A、Inbound distribute-list is configured under the ospf process and it is denying x.x.x.x
• B、ASBR origination the LSA is not reachable
• C、Route to the Forwarding Address in not an internal OSPF route
• D、Route to the Forwarding Address is an internal OSPF route
• E、Route to the ASBR does not follow the same path as the one to the Forwarding Address