Answer:
the answer is genus
Explanation: you can find it anywhere
In the medieval times, AKA the feudal system trade was very high because it was needed to get goods the kingdoms were more like places you were forced to live and without trade, you would never get food or clothes. You made less than a penny a day this could pay for a loaf of bread at the end of the week you got one pair of shoes a year and 2 pairs of clothes. When the trade went up it eventually ratified the need for all the work in the kingdoms.
This suggestion reflects a concern with causal mechanisms. The Causal mechanism is the procedures or passageways over which an outcome is taken into being. There are two broad types of theories of causation which is the Humean theory which is causation as regularities and the causal-realist theory which is causation as a causal mechanism. The Humean theory embraces that causation is completely established by facts about empirical regularities among noticeable variables in which there is no fundamental causal nature, causal power or causal necessity while the causal-realist takes concepts of causal mechanisms and causal powers as essential, and holds that the undertaking of scientific research is to attain at empirically defensible theories and hypotheses about those causal mechanisms.