Which two statements about a transit AS are correct? (Choose two.)

A.
A transit AS has eBGP connection(s) to only one external AS.

B.
Routes between ASs are always exchanged via eBGP.

C.
A transit AS uses an IGP like OSPF or ISIS to propagate the external networks within the
transit AS.

D.
Core routers within a transit AS normally use default routing to reach the external networks.

E.
iBGP sessions can be established between non directly connected routers.

Explanation: