What is the mechanism that is used to allocate MAC addresses that are assigned to the VDC for the system MAC address？（）
- A NX-OS uses a random MAC address from the IEEE OUI block that is assigned to Cisco.
- B The VDC system MAC is pulled from the active supervisor and concatenated through a hash to ensure uniqueness.
- C NX-OS uses a value that is based on a range that is assigned to the SPROM of the system backplane.
- D The VDC system MAC is based on a range that is allocated to the first line card that is installed in the switch.