Amajor difference between radio waves, visible light, and gamma rays is the of the photons, which results in the different photon frequencies and wavelengths.

The sentence can be completed as follows:
"A major difference between radio waves, visible light, and gamma rays is the energy of the photons, which results in the different photon frequencies and wavelengths."

In fact, gamma rays have greater energy than visible light and visible light has greater energy than radio waves. The energy E of a photon is related to its frequency, f, by

where h is the Planck constant. We see from this formula that the higher the frequency, the greater the energy. Instead, the wavelength is inversely proportional to the frequency:

where c is the speed of light. Since the frequency is directly proportional to the energy, this means that the wavelength is inversely proportional to the energy.

A., d., and f i think