单项选择题

A.The policy map mark has been applied on a half-duplex Ethernet interface;This is not supported.
B.The policy map queue is configured on the wrong interface; it is applied on the Serial interface whereas traffic is going over the tunnel interface.
C.The class maps are wrongly configured
D.The ip nbar protocol-discover command cannot be configured together with a Service policyoutput on the serial interface.
E.This is probably a software bug