An  administrator  performs  an  audit  on  the  /usr  filesystem  and  finds  the  following  permissions：  -rwsr-xr-x  1  root  sys  514288  Jun  18  09：40  /usr/local/bin/nmon  Which  of  the  following  methods  can  the  administrator use to remove a potential security risk（）

• A、rm /usr/local/bin/nmon
• B、chmod u-s /usr/local/bin/nmon
• C、Reinstall the file from the appropriate fileset
• D、chmod go-rx /usr/local/bin/nmon