问题如下图：
选项：
A. 
B. 
C. 
利率波动怎么影响通货膨胀的一直不太清楚，麻烦解释下谢谢
解释：
NO.PZ2016010801000085问题如下The current inflation rate of Country X is 1.5%, while its centrbank believes the optiminflation rate is 2%. In orr to reathe target, centrbank of Country X shoulA.sell securities in the open market.B.increase the percentage of posits thbanks must retain reserves.C.rethe repo rate.C is correct.In orr to increase the inflation rate to the target level, centrbank cbuy securities in the open market, crease reserve requirements anrethe polirate, surepo 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入选。老师inflation 她也过低应该是怎么调整呀，为什么是和repo rate有关，谢谢。
NO.PZ2016010801000085 C减少repo rate，为啥是宽松货币政策？repo rate怎么理解？
increase the percentage of posits thbanks must retain reserves. rethe repo rate. C is correct. In orr to increase the inflation rate to the target level, centrbank cbuy securities in the open market, crease reserve requirements anrethe polirate, surepo 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入选。什么是repo rate？
为什么降低回购利率会增加通货膨胀呀？
polirate是啥概念？除了包括repo rate还有？
