问题如下：
The interest rate risk of a fixed-rate bond with an embedded call option is best measured by:
选项：
A.effective duration.
B.modified duration.
C.Macaulay duration.
解释：
A is correct.
The interest rate risk of a fixed-rate bond with an embedded call option is best measured by effective duration. A callable bond’s future cash flows are uncertain because they are contingent on future interest rates. The issuer’s decision to call the bond depends on future interest rates. Therefore, the yield-to-maturity on a callable bond is not well defined. Only effective duration, which takes into consideration the value of the call option, is the appropriate interest rate risk measure. Yield durations like Macaulay and modified durations are not relevant for a callable bond because they assume no changes in cash flows when interest rates change.
老师能不能分别说下这三个的区别
