Marginal costs. Keep in mind that marginal means on the edge of something, so the cost of producing one more unit would be on the edge. Hope this explanation helps.
God,Gold,and Glory were definite drivers for exploration. That's all I can say since there are no answer choices.
Answer:
The need for raw materials for the factories and increased food supplies for the growing population in urban centers had led to the growth of export economies around the world that had specialized in commercial extraction of natural resources and the production of food and industrial crops.
