Which two statements about a transit AS are correct?

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.