Which of the following is NOT an input device?

The reasoning behind identifying the printer as not an input device lies in the fundamental functions and classifications of computer hardware. Input devices are designed to allow users to send data or commands to a computer. Common examples include a keyboard, which allows text input; a scanner, which converts physical documents into digital format; and a microphone, which captures audio input.

In contrast, a printer serves a different role. It is classified as an output device because its primary function is to produce a physical copy of digital documents or images from a computer. Therefore, while input devices facilitate the data entry process, the printer is responsible for delivering the results of that data processing in a tangible form.