19. Which statement regarding plant auxin is correct?
(A) It is synthesized in active growing cells and transported up or down topromote cell growth.
(B) The antagonistic interactions between cytokinin and auxin shape themorphology of shoots.
(C) Accumulation of auxin in axillary buds will promote lateral shootdevelopment.
(D) When the sunlight shines on the stem with an angle, auxin willaccumulate in the lighting side of the stem to promote cell elongation.
(E) In response to gravity, auxin will accumulate in the upper side of rootsto promote cell elongation.