Among the main sources of comparative advantage are the​ following: A. climate and natural​ resources, relative abundance of labor and​ capital, technology, external diseconomies. B. climate and natural​ resources, relative scarcity of labor and​ capital, technology, external economies. C. climate and natural​ resources, relative abundance of labor and​ capital, inefficient​ technology, external economies. D. climate and natural​ resources, relative abundance of labor and​ capital, technology, external economies.