Coherent Light of Wavelength $575 \mathrm {~nm}$ Falls on a Double-Slit and the Third-Order Bright Fringe Is

Coherent light of wavelength $575 \mathrm {~nm}$ falls on a double-slit and the third-order bright fringe is seen at an angle of $6.5 ^ { \circ }$ away from the centerline. How far apart are the double slits?

A) $10 \mu \mathrm { m }$
B) $15 \mu \mathrm { m }$
C) $20 \mu \mathrm { m }$
D) $5.0 \mu \mathrm { m }$