Concept:An output device displays or gives the result of processed data from the computer.
Explanation:A joystick is used to control movement or actions in a game or program.
It sends instructions to the computer, so it is an input device, not an output device.
A monitor shows visual output.
A plotter prints large graphics and designs on paper.
A printer produces hard copies of documents and images.
Therefore, joystick is the only device that is not an output device.
Answer:A. Joystick