A light ray of wavelength $\lambda$ is passing through a pin hole of diameter $D$ and the effect is observed on a screen placed at a distance $L$ from the pin hole. The approximations of geometrical optics are applicable, if

• A

  $D \leq \lambda$
• B

  $\frac{L \lambda}{D^2}=1$
• Correct answer
  C

  $\frac{L \lambda}{D^2}< < 1$
• D

  $\frac{L \lambda}{D^2}>>1$

Hence, the correct answer is option: 'C'.