The root user utilizes the chown command to give ownership of a file to another user. What must the root user do to regain ownership of the file? a$.$ Have the new owner run chgrp and list the root user as the new owner. b$.$ Run chgrp again listing the root user as the new owner. c$.$ Nothing, because this is a one$-$way, one$-$time action. d$.$ Run chown and list the root user as the new owner.