In Young's double slit experiment, if L is the distance between the slits and the screen upon which interference pattern is observed, x is the average distance between the adjacent fringes and d being the slit separation. The wavelength of light is given by

• A

  $\frac{\mathrm{xd}}{\mathrm{L}}$

• B

  $\frac{\mathrm{xL}}{\mathrm{d}}$

• C

  $\frac{\mathrm{Ld}}{\mathrm{x}}$

• D

  $\frac{1}{\mathrm{Ldx}}$