In a Double-Slit Experiment, the Distance Between the Slits Is

Multiple Choice

In a double-slit experiment, the distance between the slits is 0.2 mm, and the distance to the screen is 150 cm. What wavelength (in nm) is needed to have the intensity at a point 1 mm from the central maximum on the screen be 80% of the maximum intensity?

A) 900
B) 700
C) 500
D) 300
E) 600