Addressing QoS design in the Enterprise Campus network for IP Telephony applications means what?

Addressing QoS design in the Enterprise Campus network for IP Telephony applications means
what?

A.
It is critical to identify aggregation and rate transition points in the network, where preferred
traffic and congestion QoS policies should be enforced

B.
Suspect traffic should be dropped closest to the source, to minimize wasting network resources

C.
An Edge traffic classification scheme should be mapped to the downstream queue
configuration

D.
Applications and Traffic flows should be classified, marked and policed within the Enterprise
Edge of the Enterprise Campus network