Monochromatic Light of Wavelength $500 \mathrm {~nm}$ Is Incident Normally on a Diffraction Grating

Monochromatic light of wavelength $500 \mathrm {~nm}$ is incident normally on a diffraction grating. If the third-order maximum of the diffraction pattern is observed at $32 ^ { \circ }$ from the centerline, what is the distance between the slits of the grating?

A) $1.4 \mu \mathrm { m }$
B) $0.93 \mu \mathrm { m }$
C) $2.8 \mu \mathrm { m }$
D) $8.5 \mu \mathrm { m }$