问题详情

Suppose the Fed buys $10 million in government securities from a commercial bank. If the required reserve ratio is 0.25, what is the maximum amount by which checkable deposits in the banking system can change？______.
A．+$10 000 000
B．+$25 000 000
C．+$40 000 000
D．-$40 000 000请帮忙给出正确答案和分析，谢谢！