What is the primary difference between short run and long run aggregate supply curves in the AD-AS model?

• A. Short run aggregate supply is vertical, while long run aggregate supply is upward sloping
• B. Short run aggregate supply is upward sloping, while long run aggregate supply is vertical
• C. Both short run and long run aggregate supply curves are vertical
• D. Both short run and long run aggregate supply curves are upward sloping

Answer: (B)