Final answer:
Changes in the price level do not influence the aggregate supply in the long run because the long-run aggregate supply curve is vertical, indicating that the economy's potential output is fixed in terms of real factors like technology and labor. Therefore, the correct option is A.
Step-by-step explanation:
Changes in the price level do not affect the level of aggregate supply in the long run. The question pertains to economic theory regarding the long-run aggregate supply (LRAS) curve, which is depicted as vertical. This indicates that in the long run, an economy's potential output is not influenced by the price level, and shifts in aggregate demand will affect only the price level, not real output. Unemployment in this economy would remain at the natural rate of unemployment, which is unaffected by price level changes, as illustrated by the vertical Phillips curve.
In summary, the long-run aggregate supply in an economy is determined by factors such as technology, the number of workers, and the amount of accumulated capital equipment. The nature of these curves is demonstrated in Figure 13.6 and Figure 26.6, which show that as aggregate demand shifts, the level of unemployment remains constant at the natural rate, and only the price level is impacted.