Which One of the Following Statements Concerning the Index of Refraction

Multiple Choice

Which one of the following statements concerning the index of refraction for a given material is true?

A) The index of refraction may be less than 1.
B) The index of refraction may be measured in nanometers.
C) The index of refraction does not depend on the frequency of the incident light.
D) For a given frequency,the index of refraction is inversely proportional to the wavelength of light in vacuum.
E) For a given frequency,the index of refraction is inversely proportional to the wavelength of light in the material.