Alargecompanyhasover500computersthatcurrentlystaypoweredonindefinitely.Noneofthesystemsareusedafterthecompanyclosesat5p.m.WhichofthefollowingwouldbetheMOSTeffectivewayforthecompanytosaveonelectricityusage？（）
A.Setthecomputersforautomaticlog-offafteronehourofinactivity.
B.Instituteapolicyofeithershutdownorsleepmodeanhourafterclose.
C.TurnontheWakeonLANfunctionalityforallcomputers.
D.Scheduleallpatchingtobedoneduringworkhours.
参考答案：B
