The correct answer is A. Scattering.
Scattering is the deflection of a beam of radiation (of any kind of wave) by particles of a much smaller wavelength. Raman scattering is a particular type of scattering in which light is scattered by particles of a much smaller wavelength. It is named after Indian physicist Sir Chandrasekhara Venkata Raman, who won the 1930 Nobel Prize in Physics for his discovery of the phenomenon in 1928.
Diffraction is the bending of waves as they pass through an opening or around an obstacle. Interference is the superposition of two or more waves to produce a resultant wave having characteristics of the two constituent waves. Polarization is the restriction of an electromagnetic wave to a single plane of oscillation.
Scattering is the most common phenomenon of radiation. It is responsible for the blue color of the sky, the redness of the sun at sunrise and sunset, and the twinkling of stars. Diffraction is responsible for the patterns seen when light passes through a slit or around an obstacle. Interference is responsible for the patterns seen when light waves from two sources overlap. Polarization is responsible for the ability of some materials to block certain types of electromagnetic waves.