When white light enters a prism, it gets split into its constituent colours. This is due to

When white light passes through a prism, it undergoes dispersion due to the varying refractive indices for different colors. This phenomenon separates the light into its constituent colors of the visible spectrum, forming a rainbow-like pattern called a spectrum. Shorter wavelengths (violet and blue) refract more than longer wavelengths (red) as they have higher refractive indices in the prism. This causes the colors to spread out. The dispersion effect is responsible for rainbows in nature and allows scientists to analyze and understand the different wavelengths present in light. In essence, the refraction of light in a prism reveals the diversity of colors that constitute white light, demonstrating the fundamental property of the varying wavelengths.

Therefore, the correct option is "different refractive index for the different wavelength of each color".