If D is the depth of water upstream of the throat above its sill, B is the width of the throat, to achieve critical flow in an open venturi flume, the theoretical maximum flow Q, is

A. Q = 1.71 $${\text{B}}{{\text{D}}^{\frac{1}{2}}}$$

B. Q = 1.71 BD

C. Q = 1.71 $${\text{B}}{{\text{D}}^{\frac{3}{2}}}$$

D. Q = 1.71 $${\text{B}}{{\text{D}}^{\frac{2}{3}}}$$

Answer: Option C