The correct answer is: B. interference
When light hits a thin film, such as an oil film on water, some of the light is reflected off the top surface of the film and some of the light is transmitted through the film and then reflected off the bottom surface. The light waves that are reflected off the top and bottom surfaces can interfere with each other, creating a pattern of light and dark bands. The color of the bands depends on the thickness of the film and the wavelength of the light.
Dispersion is the separation of white light into its component colors. This is caused by the different wavelengths of light being refracted (bent) at different angles when they pass through a material. Diffraction is the bending of light as it passes around an object. Polarization is the alignment of the electric field of light waves in a single direction.
On a rainy day, small oil films on water show brilliant colors due to the phenomenon of interference. The light waves reflected from the top and bottom surfaces of the oil film interfere with each other, creating a pattern of light and dark bands. The color of the bands depends on the thickness of the oil film and the wavelength of the light.