Answer:
C) diamond, glass, water, air
Explanation:
This is the correct order of speed of light from slowest to fastest is diamond, glass, water, air.
For this we have to know the refractive indices of these medium which is;
Diamond = 2.417
Glass = 1.517
Water = 1.333
Air = 1.0003
Refractive index is the measure of bending of light passing from one medium to another which is equal to the velocity of light c in empty space divided by its velocity v in given medium.
So that means refractive index of a medium is inversely proportional velocity of light in given medium.
That means medium having more refractive index velocity of light is low in that medium.
Diamond has highest then glass then water then air which is 2.417, 1.517, 1.333, 1.0003 respectively.
So the correct order of speed of light from slowest to fastest is diamond, glass, water, air.