Which of the following is an example of an external peripheral device?

A keyboard is indeed an example of an external peripheral device. External peripherals are devices that connect to the outside of a computer to provide input or output capabilities. Keyboards are used for user input and typically connect via USB or Bluetooth, making them an essential external component for interacting with a computer.

In contrast, the other options include devices that fall into different categories. A CD-ROM drive, while it can be external, is often considered an internal component in modern systems. A modem is typically an external peripheral as well but can also be integrated into the computer's architecture. The internal graphics card, however, is definitely an internal component as it resides on the motherboard or is plugged into a motherboard slot, lacking the characteristics of an external device.