A System p administrator is reviewing root’s command history on a development server and finds that a junior adminstrator had been attempting to correct a full file system. One of the following commands caused damage that must be corrected.  Which command was it（）

• A、rm /var/preserve/*
• B、cat /dev/null > /var/adm/cron/log
• C、> /var/adm/wtmp
• D、rm /var/adm/ras/errlog