5 Suppose you examine the central bank's balance sheet and observe that since the previous day, reserves had fallen by $100 million. In addition, on the asset side of the central bank's balance sheet, securities had fallen by $100 million. What activity did the central bank carry out earlier in the day to lead to these changes in the balance sheet? O The central bank conducted an open market sale. The central bank conducted an open market purchase. O The central bank asked for a loan. By carrying out this activity, the central bank was aiming to (Click to select) the size of the money supply