NO.PZ2018062007000063
问题如下：
In a declining interest rate environment, compared with a CMO’s Class A tranche, its Class C tranche will be repaid:
选项：
A. earlier.
B. at the same pace.
C. later.
解释：
C is correct. Lower interest rates entice homeowners to pay off their mortgages early because they can refinance at lower rates.
With a sequential-pay structure, the A tranche in a CMO will bear the first wave of prepayments until that tranche has been completely repaid its full principal investment.
At that point, the next tranche (B) will bear prepayments until that tranche has been fully repaid, and so on.
Therefore, the Class C tranche of a CMO will be repaid last, after the Class A and B tranches.
中文解析：
较低的利率诱使房主提前偿还抵押贷款，因为他们可以以较低的利率进行再融资。
在顺序支付结构下，CMO的A层级将会承受第一波提前支付，直到那部分款项全部偿还。然后B层级将承担提前偿还的风险，最后是C层级。
因此，CMO的C层级将最后被偿还，在A和B层级之后。
C层级应该是低于A层级的吧？出现提前归还时，不应该先还C级吗？
