A recurring theme in economics is that people:

A. Have unlimited resources, but limited economic wants

B. Can increase resources by limiting their economic wants

C. Have limited economic wants and limited resources

D. Have unlimited economic wants, but limited resources

The correct answer is letter "D": Have unlimited economic wants, but limited resources.

Explanation:

Scarcity is the major economic problem by which individuals have unlimited wants but depend on limited resources to fulfill them. That scenario pushes people to make trade-offs, meaning to sacrifice the satisfaction of part of a need so other desire can also be covered. Due to scarcity, individuals must find ways to allocate their resources efficiently.

D. Have unlimited economic wants, but limited resources

Explanation:

Economics studies human behaviour in relation to ends and scarce means. Wants are unlimited but the resources to satisfy these wants are limited hence the resources are used to meet the unlimited wants in order of importance (scale of preference).

The wants forgone are known as the opportunity cost of the wants that are satisfied with the limited resources.

Hence a recurring theme in economics is that people have unlimited economic wants, but limited resources.