A 2 cm diameter coin rests flat on the bottom of a bowl in which water is 20 cm deep $(\mu_w= \large\frac{4}{3})$. If the coin is viewed directly from above what is its apparently diameter?

Question

$(a)\;2\;cm \\ (b)\;1.5\;cm \\ (c)\;2.67\;cm \\ (d)\;1.67\;cm$