Q.
Each quarter of a vessel of depth $H$ is filled with liquids of the refractive indices $n_{1},\ n_{2},\ n_{3}$ and $n_{4}$ from the bottom respectively. The apparent depth of the vessel when looked normally is
A) $\frac{H\left( n_{1} + n_{2} + n_{3} + n_{4} \right)}{4}$
B) $\frac{H\left( \frac{1}{n_{1}} + \frac{1}{n_{2}} + \frac{1}{n_{3}} + \frac{1}{n_{4}} \right)}{4}$
C) $\frac{\left( n_{1} + n_{2} + n_{3} + n_{4} \right)}{4H}$