Answer:
The question may not be a fully complete question, as it should provide a list of options to pick correctly from.
However, "diffraction and interference" are phenomenon that support the wave theory of light.
Step-by-step explanation:
A wave orchestrate the transfer of energy from one point to another. Light was made up of tiny particles usually electromagnetic radiation of any wavelength.
Diffraction in light wave causes the wave to have interference with itself as a result of hindrance faced by part of the wavefront while travelling. Diffraction of waves could be noticed when waves spread after they pass through small openings, which depends on the size of the wavelength of light compared to the opening, or obscured by bending around small obstacles. An example of diffraction in light wave can be observed in X-ray.
Wave interference occurs when two waves collides while traveling along the same medium usually they may not originate from the same source. Wave interference can be destructive interference, or constructive interference.