A Population of Plants Experiences Several Years of Severe Drought

Multiple Choice

A population of plants experiences several years of severe drought. Much of the population dies due to lack of water, but a few individuals survive. You set out to discover the physiological basis for their adaptation to such an extreme environmental change. You hypothesize that the survivors have the ability to synthesize higher levels of ________ than their siblings do.

A) auxin
B) gibberellin
C) cytokinin
D) abscisic acid