Which of the following best describes positive gravitropism exhibited by plant roots?
A) It is mediated by auxin similar to the phototropism responses in shoots.
B) It depends on an inhibition of elongation of some cells.
C) Gravity causes gibberellins to accumulate on the lower side of roots.
D) The phenomenon depends upon inhibition of cell elongation of certain root cells by abscisic acid.
E) All of the above are correct.
