Refer to the exhibit. OSPF is configured on all routers in the network. On the basis of the
show ip ospf neighbor output, what prevents R1 fromestablishing a full adjacency with R2?

A.
Router R1 will only establish full adjacency with the DR and BDR on broadcast
multiaccess networks.

B.
Router R2 has been elected as a DR for the broadcast multiaccess network in OSPF
area

C.
Routers R1 and R2 are configured as stub routers for OSPF area 1 and OSPF area 2.

D.
Router R1 and R2 are configured for a virtual link between OSPF area 1 and OSPF area
2.

E.
The Hello parameters on routers R1 and R2 do not match.

Explanation:
From the output, we learn that R4 is the DR and R3 is the BDR so other routers will only
establish full adjacency with these routers. All other routers have the two-way adjacency
established.