試題詳解

13. Which of the following statements is correct?
(A) A fall in the mortgage interest rate would shift down the demand curve for new houses.
(B) The launch of a new Samsung smartphone would shift up the demand curve for existing iPhones.
(C) A fall in the oil price would shift up the demand curve for oil.
(D) A fall in the oil price would shift down the supply curve for plastics.