问题如下：
Which type of
asset-backed security is not affected by prepayment risk?
选项：
A.Auto loan ABSs
Residential MBSs
Credit card
receivable ABSs
解释：
C is correct. Because credit card receivable ABSs are backed by non-amortizing loans that do not involve scheduled principal repayments, they are not affected by prepayment risk.
A is incorrect because auto loan ABSs are affected by prepayment risk since they are backed by amortizing loans involving scheduled principal repayments.
B is incorrect because residential MBSs are
affected by prepayment risk since they are backed by amortizing loans involving scheduled principal
repayments.
不是很理解credit card为什么没有prepayment risk，可以再讲一下吗？谢谢
