问题如下图：
选项：
A. 
B. 
C. 
D. 
解释：
老师，请问可以解释一下什么是spread duration吗？
NO.PZ2019052801000105问题如下 With respeto fault risk and cret sprerisk, the ratings of bonrating agencies suMoo’s provi information concerning: fault risk only. cret sprerisk only. both fault risk ancret sprerisk. neither fault risk nor cret sprerisk. A is correct. Bonrating agencies issue ratings baseon the fault risk of the issue. Cret sprerisk is terminespread ration. 讲义中提到“Yielspreover treasury bon correlate highly with ratings”，意思不就是说yielsprea影响评级吗？反向关系，spre越大，评级越低。但是本题不选cret sprerisk 的原因是不是因为，这个risk 主要受宏观经济因素影响，所以反过来评级机构评级并不参考这个spread
With respeto fault risk ancret sprerisk, the ratings of bonrating agencies suMoo’s provi information concerning: fault risk only. cret sprerisk only. both fault risk ancret sprerisk. neither fault risk nor cret sprerisk. A is correct. Bonrating agencies issue ratings baseon the fault risk of the issue. Cret sprerisk is terminespreration. 请问这道题目对应的PPT在哪一页
