The correct answer is b) limited resources and unlimited wants.
Scarcity is a fundamental concept in economics that describes the situation where resources are finite while human wants are infinite. This means that there are not enough resources available to satisfy all our desires and needs. For instance, while we may want endless amounts of goods and services, the resources to produce them—such as land, labor, and capital—are limited. Therefore, understanding scarcity helps us to prioritize our choices and allocate resources more effectively in a world where not everything can be obtained.