A Light Ray in Material 1 Goes into Material 2

Multiple Choice

A light ray in material 1 goes into material 2. The angle of incidence in material 1 is 40.0° and the angle of refraction in material 2 is 31.0°. If the index of refraction of material 1 is 1.60, what is the index of refraction of material 2?

A) 3.20
B) 2.00
C) 1.88
D) 1.41
E) 1.20