问题如下：
Which of the following description about the money supply is incorrect?
选项：
A.The money supply curve is perfectly elastic.
B.The supply of money is determined by central bank of the country.
C.The money supply is independent of the interest rate.
解释：
A is correct. As money supply is determined by central bank, it is independent of the interest rate, therefore the money supply curve is perfectly inelastic (vertical).
考点：货币供给
解析：由于货币供应量是由央行决定的，它与利率无关，因此货币供给曲线是完全无弹性的(垂直的)。因此A选项入选。
老师问下 b为什么错了
