Light is incident formals on as oil at an incident angle of $30^{\circ}$ After moving through the oil -1, oil-2, and glass it exters water . If the refraction index of glass and water are 1.5 and 1.3 respectively . Then the angle which the ray makes with normal in water .

Question

$(a)\;\sin ^{-1}1 \\ (b)\;\sin ^{-1} \frac{1}{2} \\ (c)\;\sin ^{-1} \frac{1}{1.3}\\ (d)\;\sin ^{-1} \frac{1}{2.6}$