Refer to the exhibit. 
What is a reason for the RIB-failure?
A.
CEF is not enabled on this router.
B.
The route 10.100.1.1/32 is in the routing table, but not as a BGP route.
C.
The routing table has yet to be updated with the BGP route.
D.
The BGP route is filtered inbound and hence is not installed in the routing table.