The following statements are given about plant growth hormones
I. Cytokinins especially help in delaying senescence
II. Auxins are involved in regulating apical dominance
III. Ethylene is especially useful in enhancing seed germination
IV. Gibberellins are responsible for immature falling of leaves Which of the above statements are correct
(a) I and II only
(b) I and III only
(c) II and III only
(d) II, III, and IV only