Which of the following is a characteristic of a data center core?

Which of the following is a characteristic of a data center core?

A.
Server-to-server traffic always remains in the core layer.

B.
The recommended practice is for the core infrastructure to be in Layer 3.

C.
The boundary between Layer 2 and Layer 3 should be implemented in the aggregation layer.

D.
The Cisco Express Forwarding hashing algorithm is the default, based on the IP address and Layer 4 port.

E.
Core layer should run BGP along with an IGP because iBGP has a lower administrative distance than any IGP.