Which of these conditions should be avoided in the design that could otherwise cause the peers to flap continuously?

A planned EBGP network will use OSPF to reach the EBGP peer addresses.

Which of these conditions should be avoided in the design that could otherwise cause the peers to flap continuously?
A . An ACL blocks TCP port 179 in one direction.
B . IP addresses used to peer are also being sent via EBG
D . The OSPF area used for peering is nonbackbone (not area 0).
E . The routers are peered by using a default route sent by OSP

Answer: B