The answer is B, telephone. The other four options are all devices that transmit and receive information using electromagnetic waves. A telephone is a device that transmits and receives sound waves over a distance using wires.
X-rays are a type of electromagnetic radiation that can be used to create images of the inside of the body. Radio waves are a type of electromagnetic radiation that can be used to transmit sound and music over long distances. Computers are electronic devices that can be programmed to perform a variety of tasks. Televisions are electronic devices that can be used to watch video and listen to audio.