A ray of light passes through an equilateral prism such that the angle of incidence and the angle of emergence are equal to $\large\frac{3}{4}th$ of the angle of prism. The angle of minimum deviation is

Question

$(a)\;15^{\circ} \\ (b)\;45^{\circ} \\ (c)\;30^{\circ} \\ (d)\;60^{\circ} $