Coherent Light of a Single Frequency Passes Through a Double

Multiple Choice

Coherent light of a single frequency passes through a double slit with a separation d, to produce a pattern on a screen a distance D from the slits. What would cause the separation between adjacent minima on the screen to increase?

A) increase the index of refraction of the medium in which the setup is immersed
B) increase the separation d between the slits
C) increase the distance D
D) increase the frequency of the incident light