A lens has a power of +5 diopter in air what will be its power if completely immersed in water ? $\mu_g =\large\frac{3}{2};$$\mu_w=\large\frac{4}{3}$

Question

$(a)\;\frac{1}{3}\;D \\ (b)\; \frac{2}{3}\;D \\ (c)\;\frac{2}{3}\;D \\ (d)\;\frac{5}{3}\;D$