A

$$\frac{\rho AV^2}{g}$$

B

$$\frac{\rho AV}{g}\left(V - \frac{\pi DN}{60}\right)$$

C

$$\frac{\rho A}{g} \times \frac{\pi DN}{60}$$

D

$$\rho A\left(V - \frac{\pi DN}{60}\right)$$