[单项选择]non-root user can run rsh commands from serverA to serverB, but attempts to run rsh commands by the root user return with a permission error message. What action will resolve the problem? () A. Add root user to the /etc/hosts.equiv on serverb B. Create $HOME/.rhosts file for the root user on serverb C. Restart the rshd daemon with root enabled option on serverb D. Add entry to allow root user from serverA to the /etc/hosts.allow on serverb