An Optical Engineer Needs to Ensure That the Bright Fringes ${~m}$

Multiple Choice

An optical engineer needs to ensure that the bright fringes from a double-slit are 15.7 mm apart on a detector that is 1.70 ${~m}$ from the slits. If the slits are illuminated with coherent light of wavelength 633 nm, how far apart should the slits be?

A) 68.5 μm
B) 74.0 μm
C) 79.5 μm
D) 63.0 μm