Which of the following is not a computer input device?

• A. Keyboard
• B. Mouse
• C. Monitor
• D. Scanner

Answer: (C)

The monitor is the correct choice as it is not an input device; instead, it serves as an output device. Input devices are hardware used to send data to a computer for processing, enabling user interaction. The keyboard and mouse are prime examples as they allow users to input text and navigate the user interface, respectively. A scanner also qualifies as an input device because it converts physical documents into digital format, allowing the computer to process the scanned information.

In contrast, the monitor displays the processed data visually, making it essential for output but not for input. It presents the results of computations and operations performed by the computer, illustrating how input devices work in conjunction with output devices within a computing environment.