[Solved] The problem of scarcity is A)a problem only for poor countries. B)a problem only for economies under complete government control. C)faced by all economies. D)eliminated as the economy grows. E)not faced by free market economies. Reproductive Potential: The biological capability of an individual or species to produce offspring, contributing to the genetic diversity of a population. Erotic Plasticity: The degree to which an individual's sex drive can be changed by social, environmental, and situational factors. Fraternal Birth-Order Effect: The observation that a man is more likely to be homosexual the more older brothers he has from the same mother. Older Brothers: Typically refers to male siblings who are born before other children in a family, often associated with roles of protection, mentorship, and influence in the sibling relationship.