True one-dimensional flow occurs when___________________?

A. the direction and magnitude of the veiocity at all points are identical
B. the velocity of successive fluid par-ticles, at any point, is the same at suc-cessive 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