Which two statements about Cisco AutoQoS are true? (Choose two)

Which two statements about Cisco AutoQoS are true? (Choose two)

A.
A QoS service policy must already be enabled on the interface before Cisco AutoQoS can be enabled.

B.
Any interface at or below 1.54 Mbps is classified as a low-speed interface.

C.
AutoQoS uses Cisco network-based application recognition (NBAR) to identify various applications and traffic types.

D.
Cisco Express Forwarding (CEF) must be enabled at the interface or ATM PVC.

E.
Cisco NBAR is a prerequisite for CEF.

F.
On a serial interface, before AutoQoS is enabled, the clock rate command must be used to specify a bandwidth other than the default 1.54 Mbps.