Water coming out of the mouth of a tap and falling vertically in stream line flow forms a tapering column. i.e., the area of cross-section of the liquid column decreases as it moves down which of the following is the most accurate explanation for this-

Options

A. As the water moves down, its speed increases and hence its pressure decreases. It is then compressed by the atmosphere
B. Falling water tries to reach a terminal velocity and hence reduces the area of cross-section to balance upward and downward forces
C. The mass of water flowing past any cross-section must remain constant. Also, water is almost incompressible. Hence, the rate of volume flow must remain constant. As this is equal to velocity × area, the area decreases as velocity increases
D. The surface tension causes the exposed surface area of the liquid to decrease continuously

Answer

C