In 1893, Scientists Performed an Experiment to Determine Whether Tree

In 1893, scientists performed an experiment to determine whether tree roots actively pumped water through the xylem.They discovered that

A) trees do in fact pump water up through the roots.
B) capillary action is sufficient to explain the flow of water through roots.
C) leaves play a small role in the flow of water.
D) cohesion is principally responsible for the flow of water.
E) living cells were not necessary for the flow of water.