AsystemmustbeupgradedfromAIX5.1to5.2.Whichofthefollowingschedulingprocessesshouldbeperformed?()

A.Scheduleenoughdowntimetobackup,upgradeandreboot.

B.Backup,upgrade,thenscheduleenoughdowntimetorebootthesystem.

C.Backup,thenscheduleenoughdowntimetoupgradeandrebootthesystem.

D.Noschedulingprocessesarenecessarybecausenodowntimeisrequired.