A technician needs to connect to a remote Windows computer to troubleshoot an issue. Which built-in Windows tool provides full GUI remote access?

Correct answer: Remote Desktop Connection

Option C, Remote Desktop Connection (mstsc.exe), is the built-in Windows tool that provides a full graphical user interface session to a remote Windows computer, transmitting the entire desktop over the RDP protocol. Option A, Windows Remote Management (WinRM), is a command-line and scripting interface based on WS-Management, not a GUI tool. Option B, SSH, provides a secure terminal (text-based) shell session, not a full GUI desktop. Option D, Telnet, is an older, unencrypted terminal protocol that also provides only a text-based command interface.