From an initial situation of long-run equilibrium at full-employment real GDP, an increase in aggregate demand that is permanent will:（）
A. Increase real GDP, but not prices in the short run, while in the long run, prices will increase, nominal GDP will increase as a result and real GDP will remain at the new (short-run) higher level.
B. Increase nominal GDP, real GDP, and prices in the short run, while in the long run, prices will increase further but real GDP will decrease to its original level.
C. Increase nominal GDP, real GDP, and prices in the short run and in the long run.
参考答案：B
解析：
An increase in aggregate demand from an initial situation of long-run equilibrium at full-employment real GDP will (in the short-run) result in increases in nominal GDP, real GDP, and prices from a movement along the short-run aggregate supply curve. In the long run, upward pressure on resource prices from real GDP greater than potential GDP will decrease the short-run aggregate supply curve. This will lead to a decrease in real GDP back to long-run equilibrium along the long-run aggregate supply curve, resulting in an additional increase in the price level.