Concept:Scarcity is the fundamental source of all economic problems.
Explanation:Human beings have unlimited wants and needs.
However, the resources needed to satisfy these wants, such as land, labour, capital, and entrepreneurship, are limited in supply.
This limited availability of resources relative to unlimited wants is known as scarcity.
Because scarcity exists, people cannot obtain everything they desire.
They are therefore forced to make choices and rank their needs in order of importance.
These choices give rise to other economic concepts, such as opportunity cost and the scale of preference.
Thus, scarcity is not just an economic problem itself, but the root from which every other economic problem develops.
Answer:B. Scarcity.