Explanation
The administrator should use an IP KVM to access the server's console remotely for bare-metal maintenance.
An IP KVM stands for Internet Protocol Keyboard Video Mouse, which is a device that allows remote control of a server's keyboard, video, and mouse over a network connection, such as LAN or Internet. An IP KVM enables an administrator to perform tasks such as BIOS configuration, boot sequence selection, operating system installation, etc., without being physically present at the server location.
The other options are not suitable for bare-metal maintenance because they require either physical access to the server (a crash cart) or an operating system running on the server (VNC, RDP, SSH). A crash cart is a mobile unit that contains a monitor, keyboard, mouse, and cables that can be plugged into a server for direct access to its console. VNC stands for Virtual Network Computing, which is a software that allows remote desktop sharing and control over a network connection using a graphical user interface (GUI). RDP stands for Remote Desktop Protocol, which is a protocol that allows remote desktop access and control over a network connection using a GUI or command-line interface (CLI). SSH stands for Secure Shell, which is a protocol that allows secure remote login and command execution over a network connection using a CLI.