中等ECON-GDPA-012
Oil prices rise and aggregate demand is unchanged. In the short run:
A. SRAS shifts left: the price level rises and real output falls✓ 答案
B. AD shifts right
C. The price level falls and real output rises
D. Only a single-good demand curve becomes steeper
解說
A higher input cost shifts short-run aggregate supply left. That is the cost-push case: a higher price level with lower real output. It is not a shift of AD.