单项选择题

A.TCP Intercept is configured in AS 4.
B.Unicast Reverse Path Forwarding is configured in loose mode in this router.
C.Packets may be leaving AS 1 without the BGP routing flag set to 1.
D.Unicast Reverse Path Forwarding is configured in strict mode in this router.
E.There is a missing Unicast Reverse Path Forwarding configuration.