Correct answer: (d) X-rays
Explanation
- A
Visible light
Visible light is a narrow mid-band of the electromagnetic spectrum. Its photons carry less energy than ultraviolet or X-ray photons. This option is not the key.
- B
Infrared rays
Infrared rays have longer wavelength and lower frequency than visible light, so still less energy per photon. This option is therefore wrong.
- C
Ultraviolet rays
Ultraviolet rays are more energetic than visible light but less energetic than X-rays of typical diagnostic and hard bands. Among the four listed, ultraviolet is not the maximum. This option is not the key.
- D
X-rays
X-rays have shorter wavelength and higher frequency than ultraviolet, so the highest photon energy in this list. Energy of a photon rises with frequency. This option is the official key.
Summary. Official key is (d) X-rays. Photon energy increases from infrared through visible and ultraviolet to X-rays. Gamma rays would be higher still, but they are not among the options. Visible and infrared are too soft; ultraviolet is intermediate. Only X-rays have the maximum energy here.