Which of these is an example of an external peripheral device?

A keyboard is indeed an example of an external peripheral device because it is an input device that connects to a computer or similar system from the outside and allows users to interact with the system by entering data or commands. Peripheral devices like keyboards are designed to enhance the functionality of the computer by providing a means for the user to input information.

In contrast, other options represent different components with distinct roles. A microprocessor is the central processing unit of a computer and is internal to the system, responsible for executing instructions. A hard drive, while it may seem external if referring to an external hard drive, is typically classified as a storage device that can be internal or external based on its connection. RAM, or Random Access Memory, is also an internal component of the computer, serving as a temporary storage area for data currently being used or processed. This internal nature of the microprocessor, hard drive, and RAM distinguishes them from the keyboard, underscoring the importance of identifying external peripheral devices in the context of user interaction with computer systems.