Gamma: 4
Infrared: 1
X-Ray: 3
Visible Light: 2
Infrared has the longest wavelength between the four options, meaning that it has the lowest frequency. Since the longer the frequency, the lower the frequency. While the shorter the wavelength, the higher the frequency.
Next would be visible light since it has the second longest wavelength out of the given options. Then it would be X-Ray. And finally Gamma since it has the shortest wavelength.
