An L-shaped glass tube is just immersed in flowing water such that its opening is pointing against flowing water. If the speed of water current is v, then

• A

  The water in the tube rises to height $\frac{{\mathrm{v}}^2}{2\mathrm{g}}$

• B

  The water in the tube rises to height $\frac{\mathrm{g}}{2{\mathrm{v}}^2}$

• C

  The water in the tube does not rise at all 

• D

  None of these