Monochromatic Light Is Normally Incident on a Diffraction Grating That $\degree$

Multiple Choice

Monochromatic light is normally incident on a diffraction grating that is 1 cm wide and has 10,000 slits. The first order line is deviated at a 30 $\degree$ angle. What is the wavelength, in nm, of the incident light?

A) 300
B) 400
C) 500
D) 600
E) 1000