Whileusingthesmitinstall_removemenustoremovesomefilesetsonanAIX5.3server，asystemadministratornoticesthe/usrfilesystemisnowunnecessarilylarge.Whichofthefollowingactionswillreducethesizeofthe/usrfilesystem（）

A.Backup，unmount，remove，recreateandrestorethefilesystem.

B.BootfrommksysbtapeandselectShrinkfilesystemsonrestore.

C.Unmount，rundefragfs/usrandthereducefs-sizen/usrcommands.

D.Updatethe/image.datafilewiththedesiredsizefor/usrandrebootthesystem.