问题
单项选择题
On January 5, the U. S. Federal Reserve (the Fed) bought $10000000 of U. S. Treasury securities in the open market. At the time, the reserve requirement was 25 percent, and all banks had zero excess reserves. What is the potential impact of the Fed’ s purchase on the U. S. money supply（）
A. $ 25000000 decrease.
B. $ 40000000 increase.
C. $ 10000000 increase.
答案
参考答案：B
解析：
Buying securities by the Fed increases the money supply because they are injecting money into the banking system. The money supply can potentially increase by 1/0.25×$ 10000000=$ 40000000.