问题如下图：
选项：
A. 
B. 
C. 
D. 
解释：
助学贷款跟房贷有区别吧，感觉更像汽车贷。为什么B不对
Whiof the following measures are most likely to usea securitizeprobackestunt loans? Single monthly mortality (SMM), constant prepayment rate (CPR), anPublic Securities Association (PSA). Loss curves anabsolute prepayment spee(APS). Weighteaverage life (WAL), weighteaverage maturity (WAM), anweighteaverage coupon (WAC). servicoverage ratio (CR) anmonthly payment rate (MPR). A The constant prepayment rate (CPR) anthe Public Securities Association (PSmethoare common methologies useto estimate prepayments for stunt loans anmortgages. stunt loan也算是一种信用贷款啊，应该更加考虑的是cret risk啊，smm cpr考虑的都是prepayment risk啊
stunt loans有什么特点？为什么可以用第一种方法？
