Which one of the following acids is a derivative of carotenoids?
(a) Indole-butyric acid
(b) Indole-3-acetic acid
(c) Gibberellic acid
(d) Abscisic acid
Abscisic acid is a terpenoid, i.e. a derivative of Steroid. Indole butyric acid and indole-3-acetic acid are
auxins, which are weak organic acids. Gibberellic acid (gibberellin) is a terpene.