Refer to Figure 4.1, which shows Molly's and Ryan's individual demand curves for compact discs per month. Assuming Molly and Ryan are the only consumers in the market, what is the market quantity demanded at a price of $9?

Jack exported a rare painting illegally. This transaction will:

A) cause the GDP of his country to increase. B) not affect the calculation of his country's GDP. C) cause the GDP of the country he has exported it to increase. D) cause the GDP of his country to decrease.

If opportunity costs are ________, the production possibilities frontier would be graphed as a negatively sloped straight line

A) increasing B) constant C) decreasing D) negative