Using the aggregate demand–aggregate supply model, predict what happens in the short run when the consumer confidence index falls as consumers become pessimistic about their economic prospects?a. The aggregate supply curve shifts right; the aggregate demand curve is not affected; price level decreases; real GDP increases. b. The aggregate demand curve shifts right; the aggregate supply curve is not affected; price level and real GDP increase. c. The aggregate demand curve shifts left; the aggregate supply curve is not affected; price level and real GDP decrease.