Concept:The economic problem exists because human wants are unlimited while the resources needed to satisfy them are limited, that is, scarce.
Explanation:Every society faces the basic economic problem of allocating scarce resources among competing uses.
Scarcity makes it impossible to satisfy all wants, so individuals and societies must decide what to produce, how to produce, and for whom to produce.
Though choice and opportunity cost follow from scarcity, they are not the original cause of the problem.
If resources were unlimited, no choices would be necessary and no opportunity costs would arise.
Thus, scarcity is the fundamental reason behind the economic problem.
Answer:D. Scarcity