Which three roles are predefined in the Cisco UCS system?（）

A.SFPs
B.BIOS firmware
C.cluster firmware
D.Fabric Interconnect
E.Baseboard Management Controller （BMC）

A.By using active / passive teaming with spanning tree on the active link
B.By using active / passive teaming with only the active link in use
C.By using active / active teaming with VM utilizing both uplink ports