While upgrading an existing x445 with a second SMP expansion module and four processors， a technician notices the SMP connector cables are missing on the back， so the technician connects the cables. Upon powering up， the technician notices the upper SMP expansion module is disabled. Which of the following is the most likely cause of the problem？（）

A. The system requires 220V power to enable the upper SMP expansion module.
B. The technician cabled the SMP expansions wrong.
C. The Xcel4 cache needs to be reset in the BIOS because of the addition of the second SMP expansion module.
D. If no hardware licenses keys have been purchased for the processors in the upper SMP expansion module， it will not be activated.