Which process describes light spreading as it passes through a narrow opening or around obstacles?

The correct answer, which describes the process of light spreading as it passes through a narrow opening or around obstacles, is diffraction. This phenomenon occurs when a wave encounters an obstacle or a slit that is comparable in size to its wavelength. Instead of traveling in straight lines, the light waves bend and spread out, creating a pattern of interference, which can be observed as bands of light and dark.

Diffraction is most noticeable with waves of longer wavelengths, such as sound and light, especially at small openings. In contrast, the other processes listed, such as reflection (the bouncing of light off surfaces), dispersion (the separation of light into its component colors, such as through a prism), and refraction (the bending of light as it passes from one medium to another with a different density), do not involve the spreading of light around obstacles in the same manner.