A transparent block A having refractive index $$\mu = 1.25$$ is surrounded by another medium of refractive index $$\mu = 1.0$$. A light ray is incident on the flat face of the block with incident angle $$\theta$$. What is the maximum value of $$\theta$$ for which light suffers total internal reflection at the top surface of the block?

A

$$\tan^{-1}(4/3)$$

B

$$\tan^{-1}(3/4)$$

C

$$\sin^{-1}(3/4)$$

D

$$\cos^{-1}(3/4)$$