Which of the Following Observations Provides the Strongest Evidence Against

Which of the following observations provides the strongest evidence against root pressure being the principal mechanism of water transport in the xylem?

A) A water potential gradient between roots and shoots.
B) The movement of water into the xylem from surrounding cells in the roots.
C) Not all plants have roots.
D) Not all soils have high concentrations of ions.
E) Shoots with roots removed can transport water when placed in a container of water.