14) Which of the following is true of U.S. international trade?

a.U.S. exports include crude oil and refined petroleum.

b.U.S. international trade represents about 50 percent of U.S. GDP.

c.U.S. imports of goods and services in 2011 amounted to 18 percent of GDP.

d.The U.S. economyis a closed economy.

e.Italy was one of the major trading partners of the U.S. in 2011.