How should a Linux administrator prevent the root user from logging in remotely via SSH (Secure Shell)?

How should a Linux administrator prevent the root user from logging in remotely via SSH (Secure Shell)?

A.
Add enyLogin to /root/.ssh/sshd_config

B.
Add ermitRootLogin no to /etc/ssh/sshd_config

C.
Add ermitLogin no to /root/.ssh/sshd_config

D.
Add enyRootLogin to /etc/ssh/sshd_config