You are trying to initiate an SSH connection to a remote router and are getting rejected with an error code of 0. Which of these might be the cause of the error?（）

• A、The routers are using different SSH versions.
• B、You are trying to log in using invalid credentials.
• C、The RSA key pair is not properly configured on the SSH client.
• D、The RSA key pair is not properly configured on the SSH server.