A collimated beam of light contains radiation with wavelength $420\,\text{nm}$ and radiation with wavelength $630\,\text{nm}$. It is incident normally on a diffraction grating. The diffraction maxima from the two wavelengths coincide only at an angle of $31^{\circ}$ to the direction of the incident light beam. What could the line spacing of the diffraction grating be?
- A$1.2\,\mu\text{m}$
- B$1.6\,\mu\text{m}$
- C$2.4\,\mu\text{m}$
- D$3.7\,\mu\text{m}$