问题如下：
For the issuer, a sinking fund arrangement is most similar to a:
选项：
A.term maturity structure.
B.serial maturity structure.
C.bondholder put provision.
解释：
B is correct.
With a serial maturity structure, a stated number of bonds mature and are paid off on a predetermined schedule before final maturity. With a sinking fund arrangement, the issuer is required to set aside funds over time to retire the bond issue. Both result in a pre-determined portion of the issue being paid off according to a pre-determined schedule.
此题不是很明白，请帮忙详细解释下。谢谢老师。
