问题如下图：
选项：
A. 
B. 
C. 
解释：
假如credit spread下降20bp，那么就是no change 吗？
NO.PZ201812020100001001 请问老师，我记得课上讲过对于HYbonspreahange可以抵消一部分利率的变动，那为什么spreauration不会和mofieuration相互抵消？
No, the bonprishoulcrease. No, the bonprishoulincrease. B is correct. increase in interest rates results in a crease in the bonprice. increase in the cret sprealso results in a crease in the bonprice. For the EKN bon its mofieration shows the effeof the 20 increase in interest rates. The approximate percentage prichange resulting from the increase in interest rates is –8.47 × 0.0020 = –1.694%. The spreration shows the effeof the 20 increase in the cret sprea The approximate percentage prichange resulting from the increase in the cret spreis –8.47 × 0.0020 = –1.694%. The combineeffeis a totchange of –3.388%, or a pricrease of roughly 3.4% 题目只说cret sprea化了 并没有说benchmark YTM发生了变化，为什么要从两方面计算呢？
mofieration 与 spreration 相等 可不可以理解为benchmark YTM变动对债券价格没有影响啊？如上个回答，债券YTM变化来自benchmark和sprea部分，那现在是不是说明债券YTM变化都来自sprea？不能理解为什么要把两个1.694%加在一起，mofieration已经包含sprea动带来的影响了吧？
想请教下 相关的一个问题，为什么Fixecoupon的 spreration和mofieration相等呢？
