If there is no exact match in the local routing table, what three conditions would result in BGP introducing the classful network 172.0.0.0 with the mask 255.0.0.0 into the BGP table? (Choose three.)
A. no auto-summary is configured under the router bgp {as no.} command
B. network 172.0.0.0 is configured under the router bgp {as no.} command
C. any classful network must exist in the BGP table
D. auto-summary is enabled under the router bgp {as no.} command
E. the routing table contains the subnet 172.172.172.0 with a subnet mask of 255.255.255.0
F. a classless network must exist in the BGP table
