Which two Cisco AutoQoS configuration statements are true？ （）

A. the auto discovery qos command is supported on serial interfaces， subinterfaces， and virtual interfaces
B. CEF must be enabled before configuring the auto discovery qos command
C. the auto discovery qos privilege EXEC command must be configured on a router for several days to collect a sampling of data traffic
D. the auto qos trust command relies on NBAR to provide VoIP classification
E. the auto qos voip command configures the voip classification on routers and switche