Which two design solutions ensure that the enterprise access routers reach all devices in this enterprise network?

A large enterprise company is redesigning their WAN infrastructure and has these design requirements

Which two design solutions ensure that the enterprise access routers reach all devices in this enterprise network? (Choose two)
A . Configure the access routers to send a default route to the MPLS network.
B . Summarize the routes on the MPLS WAN interfaces of the distribution routers.
C . Use prefix lists on the distribution routers to control which routes are sent to the MPLS network.
D . Configure the distribution routers to send a default route to the MPLS network.
E . Configure null routes and aggregate routes for the prefixes in your network on the distribution routers.

Answer: B,D