Which of the following is an example of output hardware?

Output hardware refers to devices that receive and present data from a computer in a form that is understandable to the user, typically through audio, visual, or tactile means. Headphones serve as a prime example of output hardware, as they convert digital audio signals from a computer into sound waves that can be heard by the user. This enables a direct auditory output, allowing users to listen to music, audio recordings, or notifications from their devices.

In contrast, a scanner and a barcode reader are classified as input devices, as they capture information and send it to a computer for processing. A microphone also serves as an input device, converting sound waves into electrical signals for the computer to process. Therefore, among the choices given, headphones distinctly fulfill the role of output hardware by providing auditory feedback to the user.