Answer:
C) Index of refraction
Explanation:
Index of refraction also known as refractive index is defined as speed of light in a vacuum divided by the speed of light in a given material.
The formula for Index of refraction is:
n = c ÷ v
where n represents Index of refraction,
c represents speed of light in a vacuum,
v represents speed of light in a given material.
The speed and direction of light changes when it moves from one medium to another. The change in direction is basically called refraction.
