问题如下：
With respect to floating-rate bonds, a reference rate such as the London interbank offered rate (Libor) is most likely used to determine the bond’s:
选项：
A. spread.
B. coupon rate.
C. frequency of coupon payments.
解释：
B is correct.
The coupon rate of a floating-rate bond is expressed as a reference rate plus a spread. Different reference rates are used depending on where the bond is issued and its currency denomination, but one of the most widely used set of reference rates is Libor. A and C are incorrect because a bond’s spread and frequency of coupon payments are typically set when the bond is issued and do not change during the bond’s life.
老师您好，请教一下A是什么意思，麻烦啦
