What is the purpose of the L1/L2 ports on the 6120 Fabric Interconnect?

What is the purpose of the L1/L2 ports on the 6120 Fabric Interconnect?

A.
Supports LACP

B.
Carries cluster heartbeat messages

C.
Used for out-of-band Management

D.
Connects directly to the 2104 Fabric Extender