Suppose the equilibrium price for a good is $4 and the government imposes a price ceiling at $2. At the price ceiling, the quantity supplied is 600 and the quantity demanded is 1,000. Which of the following is true? O At the price ceiling the surplus equals 400 units. O At the price ceiling the surplus equals 300 units. O At the price ceiling the shortage equals 400 units. O At the price ceiling the shortage equals 200 units.