What happens to the quantity supplied and quantity demanded when an effective price ceiling is imposed below the equilibrium price?

• A. Both quantity supplied and quantity demanded increase, leading to equilibrium.
• B. Both quantity supplied and quantity demanded decrease, leading to a shortage.
• C. Quantity supplied increases and quantity demanded decreases, leading to a surplus.
• D. Quantity supplied decreases and quantity demanded increases, leading to a shortage.

Answer: (D)