A 500 Nm Light Is Reflected Constructively from a Thin

Multiple Choice

A 500 nm light is reflected constructively from a thin layer of oil of index of refraction 1.25, which rests on the top of water of index of refraction 1.33. What is the minimum thickness of the layer of oil?

A) 100 nm
B) 150 nm
C) 175 nm
D) 200 nm
E) 225 nm