A. You use SAS expansion port EXP1 and reserve SAS expansion port EXP2 for a second drive expansion stack.

B. The controller A and the controller B SAS expansion ports (EXP1 & EXP2) should be divided between the A-side and B-side IOM-12 modules for all the expansion shelves.

C. The controller A and the controller B SAS expansion ports (EXP1 & EXP2) should not be divided between the A-side and B-side IOM-12 modules for all of the expansion shelves.

D. You use SAS expansion port EXP2 and reserve SAS expansion port EXP1 for a second drive expansion stack.