Which statement about data center access layer design modes is correct?

Which statement about data center access layer design modes is correct?

A.
The access layer is the first oversubscription point in a data center design.

B.
When using a Layer 2 loop-free design, VLANs are extended into the aggregation layer.

C.
When using a Layer 2 looped design, VLANs are not extended into the aggregation layer.

D.
When using a Layer 3 design, stateful services requiring Layer 2 connectivity are provisioned from the aggregation layer.

E.
The data center access layer provides the physical-level connections to the server resources and only operates at Layer 3.