Which of the following BEST describes a SAP when regarding QoS?

A. A point in the network where EXP bits can be mapped to one of eight predefined FCs, each one with its own queue.
B. A logical point in a service tunnel where all of customer traffic is aggregated.

C. A point at which the initial classification of customer traffic occurs.

D. A point in the network where QoS parameters are discarded in favor of lower-level hardware queuing functions, such as LLI (Link Layer Interleave).
E. A point in the network where traffic flows from multiple different services are queued together, based on forwarding class.