You are troubleshooting a problem where external routes are not being summarized into the OSPF backbone. Referring to the exhibit, what needs to be done to resolve this problem?

The area-range parameter needs to be under Area 0. 

The area-range parameter needs to be under the nssa hierarchy. 

The summaries parameter needs to be removed under the/issa hierarchy. 

The area-range parameter must include the override-metric parameter.