问题如下：
The CDO tranche with
a credit rating status between senior and subordinated bond classes is called the:
选项：
A. equity tranche.
B. residual tranche.
C. mezzanine tranche.
解释：
C is correct. The mezzanine tranche consists of bond classes with credit ratings between senior and subordinated bond classes.
A is incorrect because the equity tranche falls within and carries the credit rating applicable to the subordinated bond classes.
B is incorrect because the residual tranche falls within and carries the credit ratings applicable to the subordinated bond classes.
老师这个知识点可以再列一下吗？完全没印象，麻烦把题目也解析下，谢谢
这道题就问你senior和subordinate中间这一层叫什么。这算是常识哈，需要记住，没有什么逻辑推理的。