White light is made up of which of the following

The colour of visible light depends on its wavelength. These wavelengths range from 700 nm at the red end of the spectrum to 400 nm at the violet end. White light is actually made of all of the colours of the rainbow because it contains all wavelengths, and it is described as polychromatic light.

Explanation:

i think the answer is a, hope this is right, that would be my best guess.