Which one of the plant growth regulators

Which one of the plant growth regulators would you use if you are asked to
(i) Induce rooting in a twig (ii) Quickly ripen a fruit
(iii) Delay leaf senescence (iv) Induce growth in axillary buds
(v) Bolt a rosette plant (vi) Induce immediate stomata! closure in leaves?

(i) Indole Butyric Acid (IBA)
(ii) Ethylene
(iii) Cytokinin
(iv) Cytokinin
(v) Gibberellin
(vi) Abscisic acid