A) Economic scarcity is when there is a limited supply of goods and resources.

B) Although economics is a social science and not an actual science, the field did take steps to try and formalize the discipline to be more like a natural science (for better or for worse as some argue) by implementing the idea of marginalism in which the price or utility of a good or resource is reflected on just how abundant it is. That is why diamonds are more expensive than water even when water is necessary for survival while diamonds are not.