Whileupgradinganexistingx445withasecondSMPexpansionmoduleandfourprocessors，atechniciannoticestheSMPconnectorcablesaremissingontheback，sothetechnicianconnectsthecables.Uponpoweringup，thetechniciannoticestheupperSMPexpansionmoduleisdisabled.Whichofthefollowingisthemostlikelycauseoftheproblem？（）
A.Thesystemrequires220VpowertoenabletheupperSMPexpansionmodule.
B.ThetechniciancabledtheSMPexpansionswrong.
C.TheXcel4cacheneedstoberesetintheBIOSbecauseoftheadditionofthesecondSMPexpansionmodule.
D.IfnohardwarelicenseskeyshavebeenpurchasedfortheprocessorsintheupperSMPexpansionmodule，itwillnotbeactivated.
参考答案：B
