If a Macroeconomic Model Consists of Upward-Sloping Short-Run Aggregate Supply

Multiple Choice

If a macroeconomic model consists of upward-sloping short-run aggregate supply and downward-sloping aggregate demand,can it possibly generate a constant real GDP with no business cycles over time?

A) No,only a vertical short-run aggregate supply curve can produce that result.
B) No,only a horizontal short-run aggregate supply curve can produce that result.
C) Yes,but the short-run aggregate supply curve must never shift.
D) Yes,if the aggregate demand and short-run aggregate supply curves shift in perfect unison.