How can you configure R6 so that traffic returns to subnet 172.16.6.0/24 via R5?

Refer to the exhibit.

How can you configure R6 so that traffic returns to subnet 172.16.6.0/24 via R5?
A . Advertise prefix 172.16.6.0/24 to neighbor R5 with metric 80.
B . Advertise prefix 172 16.6 0/24 to neighbor R5 with AS 65006 prepended
C . Configure the neighbor 10.5.6.5 send-community standard command
D . Set the local preference for all prefixes received from neighbor R5 to 200

Answer: C