Correct Answer:
D. All
An input device is a piece of hardware used to provide data and control signals to an information processing system, such as a computer. These devices enable interaction between the user and the computer. The question asks to identify input devices from the given options.
- Mouse: A pointing device that detects two-dimensional motion relative to a surface, translating that motion into the movement of a pointer on a display. It is a primary input device for graphical user interfaces.
- Scanner: An input device that optically scans images, printed text, handwriting, or an object, and converts it into a digital image.
- Keyboard: A primary input device used to enter text, characters, and other commands into a computer or other electronic device.
Since the mouse, scanner, and keyboard all serve the function of sending data or commands to a computer, they are all considered input devices. Therefore, the correct option is All, as it encompasses all the listed items.