A technician requires graphical remote access to various Windows, Linux, and macOS desktops on the company LAN. The security administrator asks the technician to utilize a single software solution tha

NC (Netcat) is a command-line network utility, not a graphical remote access tool.

RMM (Remote Monitoring and Management) solutions often rely on cloud services and internet connectivity for their full feature set, which conflicts with the 'no external internet connection' requirement.

RDP (Remote Desktop Protocol) is a widely used protocol for graphical remote access, primarily for Windows, but clients are available for Linux and macOS. With appropriate server implementations (e.g., xrdp on Linux) or client-side capabilities, a single RDP client can be used to connect to these diverse operating systems over a local area network without requiring an external internet connection.

SSH (Secure Shell) provides text-based command-line access by default, not graphical remote access unless used for tunneling other graphical protocols like VNC or X11, which would require additional software.