The processes of water flow in xylem and sugar translocation in phloem differ in many respects. Which of the following is not a difference between xylem and phloem transport?

A) Xylem transport always occurs in the same direction; phloem transport does not.
B) Xylem transport is a wholly passive process; phloem transport includes active energy- requiring) processes.
C) Water potential gradients are required for xylem transport to occur, but not for phloem transport.
D) Cells through which xylem transport occurs are "dead" at maturity; those in phloem transport are "alive."