Which circumstance most directly resulted from the fall of the western roman empire? the expansion of commerce the conquest of muslim lands by crusaders the migration of people from rural to urban areas the formation of feudal kingdoms

You could say that the correct answer is the formation of feudal kingdoms. Governments became decentralized because of the local nobles who grew stronger due to wealth and commerce. Muslims conquered sacred lands which led to the fall of the Eastern Roman empire. Migration went in the opposite direction, people moved to farms and not into cities.