Correct Answer  Option 1 :
\(\frac{1}{{{\lambda ^4}}}\)

Scattering of light: The phenomenon in which the light ray is redirected in all other directions on passing through particles of dimensions comparable to the wavelength of the light used is called scattering of light.

Rayleigh scattering: The scattering of light off of the molecules of the air that can be extended to scattering from particles up to about a tenth of the wavelength of the light used is called Rayleigh scattering.
According to Rayleigh scattering:
\(Intensity\;of\;scattered\;light\;\left( I \right) \propto \;\frac{1}{{{\lambda ^4}}}\)
Where λ is wavelength of light.
So, the correct option is \(\frac{1}{{{\lambda ^4}}}\)