Which one of these statements is true concerning the data center distribution (aggregation) layer
design?

A.
With Layer 3 at the aggregation layer, the physical loops in the topology must still be managed
by STP.

B.
The boundary between Layer 2 and Layer 3 must reside in the multilayer switches, independent
of any other devices such as firewalls or content switching devices.

C.
A mix of both Layer 2 and Layer 3 access is sometimes the most optimal.

D.
In a small data center, the aggregation layer can connect directly to the campus core,
exchanging IP routes and MAC address tables.

Explanation: