What are the 1U, rack mountable, Fabric Extenders (FEX) used for in a FlexPod environment?
A. to allow for the UCS C-Series to be connected to the Fabric Interconnects
B. to allow for the UCS S-Series to be connected to the Fabric Interconnects
C. to allow for extra UCS Blade Chassis to use the Fabric Interconnects
D. to allow for the UCS B-Series to be connected to the Fabric Interconnects