此题不理解，请老师讲解一下，谢谢。

问题如下：

Duration is most accurate as a measure of interest rate risk for a bond portfolio when the slope of the yield curve:

选项：

A.

stays the same.

B.

increases.

C.

decreases.

解释：

Correct Answer: A

Duration measures the change in the price of a portfolio of bonds if the yields for all maturities change by the same amount; that is, it assumes the slope of the yield curve stays the same.