问题如下：
The current inflation rate of Country X is 1.5%, while its central bank believes the optimal inflation rate is 2%. In order to reach the target, central bank of Country X should:
选项：
A.sell securities in the open market.
B.increase the percentage of deposits that banks must retain as reserves.
C.reduce the repo rate.
解释：
C is correct.
In order to increase the inflation rate to the target level, central bank can buy securities in the open market, decrease reserve requirements and reduce the policy rate, such as repo rate.
考点：Tools of Monetary Policy.
解析：为了将通货膨胀率提高到目标水平（1.5%到2%），央行可以使用在公开市场上购买证券，降低准备金率，降低回购利率等政策利率等方法，因此只有C选项入选。
When the central bank buys securities in the market, securities are replaced by cash in investor accounts, banks will have excess reserves, the money supply will increase, and interest rate will decrease, the inflation rate will increase, reserve requirements decrease and the policy rate decreases.
这句话的哪些逻辑是错的？依据是？
the policy rate 和interest rate和 inflation rate的区别？
