Answer:
Diffraction pattern are due to interference.
Step-by-step explanation:
Diffraction patterns are due to interference. Diffraction is the process of bending of light when it reaches the obstacle. A diffraction pattern is formed at the screen in which there are some bright and dark band.
Diffraction can be done using single slit, diffraction grating and double silt. Hence, the correct option is (a) "interference ".