问题如下：
Which of the following RMBS is most likely to use credit enhancement to reduce credit risk?
选项：
A.Non-agency RMBS.
B.Agency RMBS.
C.ABS.
解释：
A is correct.
Non-agency RMBS use credit enhancement to reduce credit risk, while the credit risk of agency RMBS is reduced by the guarantee of the GSE itself.
为啥ABS不用Creidt enhancement？
