Find maximum angle that can be made in glass medium $(\mu =1.5)$ if a light ray is refracted from glass to vacuum.

Question

$(a)\;\sin^{-1} \frac{2}{5} \\ (b)\;\sin ^{-1} \frac{2}{3} \\ (c)\;\sin ^{-1} \frac{3}{5} \\ (d)\;\sin ^{-1} \frac{4}{5}$