问题如下：
The yield-to-maturity of bond A is 6%. If YTM increases to 7%, its price falls 4%; if YTM decreases to 5%, price will increase:
选项：
A.equal to 4%
B.more than 4%
C.less than 4%
解释：
B is correct.
When it comes to a bond's price, the increasing percentage of price is greater than the decreasing percentage.
这道题目是根据老师讲过的“涨多跌少”吗？为什么会选B呢？
