ASystempadministratorisreviewingroot’scommandhistoryonadevelopmentserverandfindsthatajunioradminstratorhadbeenattemptingtocorrectafullfilesystem.Oneofthefollowingcommandscauseddamagethatmustbecorrected.Whichcommandwasit（）
A.rm/var/preserve/*
B.cat/dev/null>/var/adm/cron/log
C.>/var/adm/wtmp
D.rm/var/adm/ras/errlog