Refer to the exhibit.

This new OSPF network has four areas, but the hub-and-spoke area experiences frequent
flapping. You must fix this design failure. Which two mechanisms can you use to isolate the data
center area from the hub-and-spoke area without losing IP connectivity? (Choose two.)

A.
Make the DC area totally stub.

B.
Make the DC area an NSSA.

C.
Convert the DC area to EIGRP protocol.

D.
Deploy a prefix summarization on router D.

E.
Use OSPF distribute-list filtering on router A.