What is a prerequisite when configuring AutoQoS on a Cisco router?

A.
If a QoS policy exists on an interface, the interface needs to be enabled with CEF.

B.
The SNMP community string “AutoQoS” need to be configured with “read” permission only.

C.
CEF must be disabled, unless a currnet QoS policy exists.

D.
No QoS policies can exist on the interface.