Light from a single wavelength source is incident normally on a diffraction grating. For each order of diffraction $n$, the diffraction angle $\theta$ is measured. The separation between neighbouring slits in the diffraction grating is $d$. A graph is drawn in order to find the wavelength of the light. Which graph should be drawn, and how is the wavelength obtained from the graph?
- Ay-axis: $n$; x-axis: $d\sin\theta$; wavelength: gradient
- By-axis: $n$; x-axis: $d\sin\theta$; wavelength: $1/\text{gradient}$
- Cy-axis: $\sin\theta$; x-axis: $d/n$; wavelength: gradient
- Dy-axis: $\sin\theta$; x-axis: $d \times n$; wavelength: $1/\text{gradient}$