Which description is correct about traffic policing?

A.
It is mandatory when enabling NBAR and CBWFQ.

B.
It is also referred to as "buffer tuning" and is an optinal way to manage router I/O memory.

C.
It allows for the metering and limitation of bandwidh utilization.

D.
It allows for the provision of low latency on congested interfaces.

Explanation:
Traffic policing is the process of monitoring network traffic for compliance with a traffic contract and taking steps to enforce that contract. Traffic sources which are aware of a traffic contract may apply traffic shaping to ensure their output stays within the contract and is thus not discarded. Traffic exceeding a traffic contract may be discarded immediately, marked as non-compliant, or left as-is, depending on administrative policy and the characteristics of the excess traffic.