问题如下图：
选项：
A. 
B. 
C. 
解释：
老师请问这两个货币制度之间的区别是什么？现在只知道共同点是都可以小范围的浮动。
NO.PZ2016010802000215 问题如下 In practice, both a fixeparity regime ana target zone regime allow the exchange rate to flowithin a banarounthe parity level. The most likely rationale for the banis ththe banallows the monetary authority to: A.less active in the currenmarket. B.earn a spreon its currentransactions. C.exercise more scretion in monetary policy. is correct.Fixeexchange rates impose severe limitations on the exercise of inpennt monetary policy. With a rigiy fixeexchange rate, mestic interest rates, monetary aggregates (e.g., money supply), ancret contions are ctatethe requirement to buy/sell the currenthe rigiparity. Even a narrow banarounthe parity level allows the monetary authority to exercise some scretionary control over these contions. In general, the wir the ban the more inpennt control the monetary authority cexercise.考点Exchange Rate Regimes解析如果本国的货币贬值了，那我该国当局就应该在外汇市场上买本国国币，卖外国货币。这本质上等于政府实施了一个货币政策。那其实就是政府的货币政策被绑架了。如果汇率目标是带有浮动的，比如6.2-6.5这个区间浮动，现在汇率从6.4下跌到6.3，那么此时政府就不用在外汇市场进行干预。那么它的货币政策就比较具有自主性。
NO.PZ2016010802000215问题如下In practice, both a fixeparity regime ana target zone regime allow the exchange rate to flowithin a banarounthe parity level. The most likely rationale for the banis ththe banallows the monetary authority to:A.less active in the currenmarket.B.earn a spreon its currentransactions.C.exercise more scretion in monetary policy. is correct.Fixeexchange rates impose severe limitations on the exercise of inpennt monetary policy. With a rigiy fixeexchange rate, mestic interest rates, monetary aggregates (e.g., money supply), ancret contions are ctatethe requirement to buy/sell the currenthe rigiparity. Even a narrow banarounthe parity level allows the monetary authority to exercise some scretionary control over these contions. In general, the wir the ban the more inpennt control the monetary authority cexercise.考点Exchange Rate Regimes解析如果本国的货币贬值了，那我该国当局就应该在外汇市场上买本国国币，卖外国货币。这本质上等于政府实施了一个货币政策。那其实就是政府的货币政策被绑架了。如果汇率目标是带有浮动的，比如6.2-6.5这个区间浮动，现在汇率从6.4下跌到6.3，那么此时政府就不用在外汇市场进行干预。那么它的货币政策就比较具有自主性。 老师，我想问一下，关于这道题，如果浮动和固定汇率波动都比较大，那是不是就可以赚一个sprea那为什么B不对呢。
NO.PZ2016010802000215 为什么a不对 根据 不就是可以不再currenmarket上过于活跃吗
请一下这道题 看不懂
