Aggregate Demand Curve Slope Steps:

• Identify the axes: vertical is price level, horizontal is real GDP.
• Observe the curve's direction: it slopes downward from left to right.
• Recall AD definition: shows quantity of goods/services demanded at different price levels.
• Confirm: downward slope due to real wealth, interest rate, and exchange rate effects.

Why C is correct:

• Downward-sloping curve matches AD law, where higher prices reduce real wealth and purchasing power, lowering quantity demanded.

Why the others are wrong:

• A: Upward slope depicts short-run aggregate supply, not demand.
• B: Vertical line represents long-run aggregate supply, insensitive to price level.
• D: Horizontal line implies perfectly elastic supply, irrelevant to AD.

Final answer: C