The content of which local file has to be transmitted to a remote SSH server in order to be able to log into the remote server using SSH keys?

The content of which local file has to be transmitted to a remote SSH server in order to be able to log into the remote server using SSH keys?
A . ~/.ssh/authorized_keys
B . ~/.ssh/config
C . ~/.ssh/id_rsa.pub
D . ~/.ssh/id_rsa
E . ~./ssh/known_hosts

Answer: C