The concept of ________ means that because of their genetic makeup, individuals differ in their responsiveness to qualities of the environment.
Correct Answer: A
Rationale: The correct answer is A, gene-environment interaction. This concept highlights that genetic factors play a role in how individuals react to environmental factors. Niche-picking (choice B) refers to the tendency of individuals to select environments that complement their genetic predispositions, not the inherent genetic differences in responsiveness. Passive correlation (choice C) involves the association between the genetic makeup of parents and the environment they provide for their children, not individual differences in responsiveness. Evocative correlation (choice D) relates to the idea that an individual's genetic traits can elicit certain responses from others in the environment, rather than individual differences in responsiveness.