Concept:Dispersion happens because different colours of light travel at different speeds inside the glass prism.
Explanation:White light is made up of several colours.
Each colour has a different wavelength and speed in glass.
This causes each colour to be refracted, or bent, by a different amount when it enters and leaves the prism.
As a result, the colours spread out into a spectrum.
This difference in speed, not hidden colours or defects, is the reason for dispersion.
Answer:B. different speeds of the colour in the glass.