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 $g$ (acceleration due to gravity),$\rho$ (density of the surrounding fluid),$\sigma$ (surface tension),and a characteristic length scale $L$ (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
  $\frac{g L^2}{\sigma \rho}$