A Monochromatic Beam of Microwaves with a Wavelength of 0

Multiple Choice

A monochromatic beam of microwaves with a wavelength of 0.052 m is directed at a rectangular opening of width 0.35 m. The resulting diffraction pattern is measured along a wall 8.0 m from the opening. What is the distance between the first- and second-order dark fringes?

A) 1.3 m
B) 1.8 m
C) 2.1 m
D) 2.5 m
E) 3.7 m