A transparent cube of side d, made of a material of refractive index $$\mu_2$$, is immersed in a liquid of refractive index $$\mu_1$$ ($$\mu_1 < \mu_2$$). A ray is incident on the face AB at an angle $$\theta$$ (shown in the figure). Total internal reflection takes place at point E on the face BC.

Then $$\theta$$ must satisfy

A

$$\theta < \sin^{-1}\sqrt{\frac{\mu_2^2}{\mu_1^2} - 1}$$

B

$$\theta > \sin^{-1}\frac{\mu_1}{\mu_2}$$

C

$$\theta < \sin^{-1}\frac{\mu_1}{\mu_2}$$

D

$$\theta > \sin^{-1}\sqrt{\frac{\mu_2^2}{\mu_1^2} - 1}$$