A、 Incorrect bandwidth configuration on router R3 prevents R2 from establishing neighbor adjacency.
B、 Incorrect bandwidth configuration on router R 5 prevents R2 from establishing neighbor adjacency.
C、 Router R3 did not reply to the query about network 10.1.1.0/24 sent by router R2 .
D、 Router R5 did not reply to the query about network 10.1.1.0/24 sent by router R2 .