The answer is E. X-ray.
Radio, television, computer, and telephone are all electronic devices that are used to communicate or transmit information. X-ray is a type of radiation that is used for medical imaging.
Radio is a device that uses electromagnetic waves to transmit sound. Television is a device that uses electromagnetic waves to transmit both sound and images. Computer is a device that can be programmed to carry out sequences of arithmetic or logical operations automatically. Telephone is a device that allows two people to communicate with each other over a distance by using electrical signals. X-ray is a type of radiation that is used to create images of the inside of the body.
X-rays are different from the other options because they are not used for communication or transmission of information. They are used to create images of the inside of the body.