Two dimensional flow occurs when________________?

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 and 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