A Beam of Light of Wavelength 600 Nm Is Incident

A beam of light of wavelength 600 nm is incident normally on a grating with a spacing between slits of 1.70 × 10^-4 cm.At what angle away from the centerline does a first-order maximum occur?

A) 10.5°
B) 12.1°
C) 16.4°
D) 18.2°
E) 20.7°