In rome times most people live in small cities while during the middle ages most people live in the country side all of the following are reason for this change except

In roman times most people lived in small cities, while during the middle ages most people lived in the countryside. all of the following are reasons forthis change except    people fled the urban centers because they had become too crowded and unsanitary, all otehr are correct but we must remebr that it refers to teh early middle ages