问题如下：
Your boss wants to devise a fixed-income strategy such that there is no reinvestment risk over five years. Reinvestment risk will not occur if:
I. Interest rates remain constant over the time period the bonds are held.
II. The bonds purchased are callable.
III. The bonds purchased are issued at par.
IV. Only zero-coupon bonds with a five-year maturity are purchased.
选项： I
only
I and II only
C.Ill only
D.I and IV
解释：
ANSWER: D
Reinvestment risk occurs when the intermediate coupon payments have to be reinvested at a rate that differs from the initial rate. This does not happen if interest rates stay constant, or with zero-coupon bonds. Callable bonds can be called early, which creates even more reinvestment risk for the principal.
为什么 interest rates stay constant就没有再投资风险？
