The results of this experiment, shown on the left of the graph (area A), may be used to

A) show that these plants can live without gibberellin.
B) show that gibberellin is necessary in positive gravitropism.
C) show that taller plants with more gibberellin produce fruit (pods).
D) show a correlation between plant height and gibberellin concentration.
E) study phytoalexins in plants