What is the function of class-based marking?

A.
Marking packets is based only on CoS value, IP precedence value or DSCP value allows Layer
3 frames to be identified and distinguished from other packets.

B.
Marking frames based only on CoS value or IP precedence value allows Layer 2 frames to be
identified and distinguished from other frames.

C.
Marking frames or packets sets information in the Layer 2 and Layer 3 headers of a packet so
that the frame or packet can be identified and distinguished from other frames or packets in the
same traffic flow.

D.
Marking frames only sets information in the Layer 2 headers of a frame so that the frame can
be identified and distinguished from other packets or frames.

E.
Marking allows network devices to classify a packet or frame, based on a specific traffic
descriptor.