From the 1970s through the 1990s, the relative price of a college education has increased greatly. During the same time period, college enrollment has also increased. This evidence suggests that during this time period

Which of the following directly shifts the short-run aggregate supply curve?

A) a change in aggregate demand B) a change in the price level C) a change in resource prices D) all of the above

The current exchange rate system has which of the following characteristics?

A) The countries of the European Union have adopted the gold standard. B) Several developing countries in Asia have adopted the Bretton Woods system. C) The United States allows the dollar to float against other major currencies. D) The current global foreign exchange system is a fixed system. E) All developing countries allow their currencies to float against the dollar and other major currencies.