Capillary tube method of viscosity measurement is based on the

A. the direction and magnitude of the velocity at all points are identical
B. the velocity of successive fluid particles, at any point, is the same at successive periods of time
C. the magnitude aricf direction of the velocity do not change from point to point in the fluid
D. the fluid particles move in plane or parallel planes and the streamline pat-terns are identical in each plane
E. velocity, depth, pressure, etc. change from point to point in the fluid flow