Answer: The light wave is bending around an obstacle or through a barrier shows diffraction.
Explanation :
Light is one of the forms of energy. It enables us to see objects clearly. It shows many phenomena like the reflection of light, refraction, interference, diffraction etc.
The light rays bend when it passes through a narrow opening or obstacles. The essential condition for the diffraction is that the size of an obstacle should be comparable to the wavelength of light.
Hence, the correct option is (a) " The light wave is bending around an obstacle or through a barrier".