The table above shows the marginal costs and marginal benefits of college education. The efficient amount of enrollment is

One of the principles behind the concept of the circular flow is that

A) in every economic exchange, the seller receives exactly the same amount that the buyer spends. B) in every economic exchange, the seller receives less than the amount that the buyer spends. C) in exchange involving products, the seller receives less than the amount the buyer spends, but in resource markets the seller receives more than the buyer spends. D) the seller of goods receives exactly the same amount that the buyer spends, but the seller of resources receives less than the buyer spends.

Other factors held constant, a decrease in resource prices will shift the aggregate:

A. demand curve leftward. B. demand curve rightward. C. supply curve leftward. D. supply curve rightward.