两个数字对比，当子项数值和母项数值差别很（)时，常用倍数表示;差别很（)时，常用系数表示。

A. whose coupon rate will increase as market rates decrease and decrease as market rates increase.
B. that may, under certain circumstances, require the bondholder to make payments to the issuer.
C. whose coupon is determined by subtracting a reference rate from some stated maximum rate.
D. that has an implicit cap on the maximum coupon rate and typically includes a floor on the minimum coupon rate.