7.Aconical tank with a bottom opening of cross-sectional area A is filled with water and is mounted on supports as shown in the figure. What is the force F with which plate X must be pushed up to prevent water from leaking? Assume that the density of air is negligible as compared to the density of water pL. Support (A) PL• Vg (B) PL• Vg/2 (C) PL• A·Hg (D) pL• AHg/2