13. Which of the following statements is necessarily false；
(A) Monetary policy can be conducted through open market operations, setting the minimumreserve requirement and through changing the refinancing rate at which banks can borrow moneyfrom the central bank.
(B) In the short run, an increase in money supply causes a proportional increase in prices. Overtime the latter decrease again.
(C) Unemployment benefits are automatic stabilizers.
(D) The positive effect of expansionary fiscal policy on production is reduced by crowding out.