Light of Wavelength 480 Nm Falls on a Slit of Width

Multiple Choice

Light of wavelength 480 nm falls on a slit of width 3.5 µm.What is the relative intensity (that is, the value of I/I_m) of the diffraction pattern at an angle of 18°?

A) 2.4 x 10^-4
B) 1.7 x 10^-3
C) 1.1 x 10^-2
D) 1.0 x 10^-1
E) 1.0