A liquid flows through a horizontal tube. The velocities of the liquid in the two sections, which have areas of cross - section A1 and A2, are V1 and V2 respectively. The difference in the levels of the liquid in the two vertical tubes is h.a) The volume of the liquid flowing through the tube in unit time is A1V1.b) c) d) The energy per unit mass of the liquid is the same in both sections of the tube.