Young-Laplace law states that the excess pressure inside a soap bubble of radius $R$ is given by $\Delta P=4 \sigma / R$, where $\sigma$ is the coefficient of surface tension of the soap. The EOTVOS number $E_0$ is a dimensionless number that is used to describe the shape of bubbles rising through a surrounding fluid. It is a combination of $g$, the acceleration due to gravity $\rho$ the density of the surrounding fluid $\sigma$ and a characteristic length scale $L$ which could be the radius of the bubble. A possible expression for $E_0$ is 

• A

  $\frac{\rho g}{\sigma L^3}$

• B

  $\frac{\rho L^2}{\sigma g}$

• C

  $\frac{\rho g L^2}{\sigma}$

• D

  $\frac{g L^2}{\sigma \rho}$