Which of the following input devices allows multiple PCs to share a common display?

A router directs network traffic between devices and networks but does not share or switch display output between multiple computers.

A bridge connects two network segments at the data link layer and has no capability to share or switch video output between PCs.

A KVM switch acts as a hardware multiplexer that routes video signal, keyboard input, and mouse input from multiple connected PCs to a single shared display and input device set. Switching between systems is typically done via a button or hotkey sequence. This makes it the only device in the list designed specifically to share a common display across multiple PCs.

A wireless keyboard is a single input device that connects to one computer at a time and cannot share a display across multiple PCs.