Concept:An output device is computer hardware that presents processed data to the user in a readable form.
Explanation:The computer receives data from input devices and sends results to output devices.
A monitor displays text, images, and videos on a screen.
A keyboard, a mouse, and a scanner all send data into the computer, so they are input devices.
Printers, plotters, and speakers are other examples of output devices.
Among the options given, only the monitor shows the computer's output to the user.
Answer:C. monitor