On a system wide basis， which of the following procedures is best to make NIS name resolution take precedence over DNS？（）

• A、Remove the /etc/resolv.conf file
• B、Unset the NSORDER environment variable
• C、Add the following line to /etc/netsvc.conf： hosts=nis，bind，local
• D、In a NIS and DNS environment， NIS takes precedence so there is nothing to change