There are two identical small holes P and Q of area of cross-section a on the opposite sides of a tank containing a liquid of density p. The difference in height between the holes is h. Tank is resting on a smooth horizontal surface. Horizontal force which will has to be applied on the tank to keep it in equilibrium is

• A. \[gh\rho a\]        
• B. \[\frac{2gh}{\rho a}\]
• C. \[2\rho agh\]
• D. \[\frac{\rho gh}{a}\]