Final answer:
The correct expression for the short-run aggregate supply (SRAS) curve is option d. The quantity of output supplied = a(expected price level - actual price level) - natural rate of output.
Step-by-step explanation:
The correct expression for the short-run aggregate supply (SRAS) curve is option d. The quantity of output supplied = a(expected price level - actual price level) - natural rate of output.
In the short run, the SRAS curve shows the positive relationship between the price level and the level of real GDP. As the expected price level increases relative to the actual price level, firms are encouraged to produce more output, leading to an increase in the quantity of output supplied. The natural rate of output represents the level of output that can be produced when all resources are fully utilized.