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 ASB
E . External routes are propagated into the autonomous system from regular areas or NSSA via ASB
G . External routes are propagated into the autonomous system from regular areas or NSSA via AB
Answer: BD