What are the PHBs that DiffServ use?

A.
resource reservation and admission control

B.
default, AF, and EF PHBs

C.
AF, EF, and CS PHBs

D.
AF and EF PHBs

E.
default, AF, EF, and CS PHBs

Explanation:
A Per Hop Behavior refers to the packet scheduling, queuing, policing, or shaping
behavior of a node on any given packet belonging to a Behavior Aggregate, and as configured by
a Service Level Agreement (SLA) or policy. To date, four standard PHBs are available to construct
a DiffServ-enabled network and achieve coarse-grained, end-to-end CoS and QoS: The Default
PHB, Class-Selector PHBs, Expedited Forwarding PHB and Assured Forwarding PHB.
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