A customer has a Power 750 with the following: One processor card with 8 cores enabled, and 64GB RAM installed One GX+ adapter with one I/O drawer attached One 4-port 1Gbps IVE adapter PowerVM Standard Edition. They need to add a GX++ adapter and cable it to an I/O drawer. Which of the following must also be ordered?（）

• A、A second IVE adapter
• B、A second processor card
• C、PowerVM Enterprise Edition
• D、An additional cable-management arm