问题如下：
Company A has an issuer credit rating of A but its latest issued bond B has obtained a credit rating of BBB+. Which of the following may cause the difference between two credit ratings?
选项：
A.Bond B has a lower seniority ranking.
B.Bond B includes an additional conventant which can protect bondholders.
C.Bond B is influenced by the restricted status.
解释：
A is correct.
Notching, a ratings adjustment, is required when the newly issued Bond B has a lower seniority ranking.
Notching, a ratings adjustment, is required when the newly issued Bond B has a lower seniority ranking.
为什么有 lower seniority ranking？ 这不是一个债券内部的吗？为什么是一个原因？
