Which two statements best describe an OSPF deployment? (Choose two.)

A.
ABR provides automatic classful network boundary summarization.

B.
ABR requires manual configuration for classful network summarization.

C.
External routes are propagated into the autonomous system from stub areas via ASBR.

D.
External routes are propagated into the autonomous system from regular areas or NSSA via ASBR.

E.
External routes are propagated into the autonomous system from regular areas or NSSA via ABR.