How does the extended community cost feature influence the BGP best path selection?

How does the extended community cost feature influence the BGP best path selection?

A.
alters the BGP AS exit path selection by adding the link cost to the local preference

B.
acts as a best path "tie breaker" when multiple IGP equal cost paths occur

C.
reflects the bandwidth of links entering the local AS from eBGP neighbors (in the MED attribute)

D.
selects the BGP route with the highest attached extended community cost value

E.
inserts the cost attribute after the MED attribute comparison, forcing best path route selection if all other preferred route selection criteria are equal