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 switches