Air (density $\rho$) is being blown on a soap film (surface tension $T$) by a pipe of radius $R$ with its opening right next to the film. The film is deformed and a bubble detaches from the film when the shape of the deformed surface is a hemisphere. Given that the dynamic pressure on the film due to the air blown at speed $v$ is $\frac{1}{2} \rho v^{2}$,the speed at which the bubble is formed is:

• A
  $\frac{T}{\sqrt{\rho R}}$
• B
  $\sqrt{\frac{2 T}{\rho R}}$
• C
  $\sqrt{\frac{4 T}{\rho R}}$
• D
  $\sqrt{\frac{8 T}{\rho R}}$