The correct answer is - B. large empires developed.
The mountains are a natural barrier for lot of human activities, and one of those is the formation of settlements, big countries, or empires. The creation of large empires on a mountainous terrain is extremely hard and unpractical, and there's very few cases in the human history that that has been performed well. The reasons for that is that in the mountainous regions it is hard to create a network of roads, build large settlements, and also there's lack of natural resources and food, so the people had the tendency to create small settlements, or city-states in this kind of circumstances.