The odd one out is C. X-rays.
The other options, A. Infrared Rays, B. Radio waves, and D. Ultraviolet Rays, are all types of electromagnetic radiation. X-rays are a type of ionizing radiation, which means they have enough energy to remove electrons from atoms. This can damage DNA and cause cancer. The other types of electromagnetic radiation are non-ionizing, which means they do not have enough energy to remove electrons from atoms.
Infrared rays are a type of electromagnetic radiation with wavelengths longer than visible light but shorter than microwaves. They are emitted by hot objects and are used in many applications, such as night vision, infrared photography, and remote sensing.
Radio waves are a type of electromagnetic radiation with wavelengths longer than infrared light but shorter than microwaves. They are used in many applications, such as radio broadcasting, television broadcasting, and radar.
Ultraviolet rays are a type of electromagnetic radiation with wavelengths shorter than visible light but longer than X-rays. They are emitted by the sun and other hot objects and can cause sunburn, skin cancer, and other health problems.