An air bubble is at the bottom of the lake at $40m$ deep where the temperature is $6^{\circ}C$. The bubble rises to the surface where the temperature is $20^{\circ}C$ If it's volume at the bottom is $50\;cm^3$, what is its volume at the surface?

Question

Note:

Specific gravity of mercury is $13.6$
1 Atmospheric pressure = $76cm$ of Mercury

$\begin{array}{1 1} (A)246.30\;cm^3 \\ (B) 128.15\;cm^3 \\ (C) 256.30\;cm^3 \\ (D) 512.60\;cm^3 \end{array}$