A spectrum is formed by a prism of dispersive power${ }^{\text{'}}{\mathrm{\omega }}^{\mathrm{\prime }}$. If the angle of deviation is${ }^{\text{'}}{\mathrm{\delta }}^{\mathrm{\prime }}$, then the angular dispersion is

• A

  $\frac{\mathrm{\omega }}{\mathrm{\delta }}$

• B

  $\frac{\mathrm{\delta }}{\mathrm{\omega }}$

• C

  $\frac{1}{\mathrm{\omega \delta }}$

• D

  $\mathrm{\omega \delta }$