Concept:A mobile input device is one that can be held or moved easily to supply input to a computer.Explanation:Joystick, light pen, and mouse can all be held or moved to control the cursor or enter commands.This makes them mobile or hand-held input devices.A scanner works by placing it on a flat surface and feeding documents or images into it.It is not designed for hand-held movement while giving input.Thus, scanner is the device that is not a mobile input device.Answer:D. Scanner