An administrator receives the following message on a remote server: Cannot open display. Which of the following should the administrator have used to log in to the server? xrdp -h server.company.com A

The `ssh -X` flag enables X11 forwarding, which tunnels the X display protocol over the SSH connection so GUI applications on the remote server render on the local client's display. Without this flag, the remote shell has no DISPLAY variable set, causing any graphical program to fail with 'Cannot open display'. This is the standard, built-in SSH mechanism for remote GUI access without a separate protocol.

`xvnc` starts a VNC server instance on the local or remote machine; it does not establish an outbound connection to a server or provide X11 forwarding over SSH.