问题如下图：
选项：
A. 
B. 
C. 
D. 
解释：
zero coupon bond 如果在到期前提前卖了不也有利率风险吗？请问RI risk特指对当中coupon的再投资面临的利率风险吗
Your boss wants to vise a fixeincome strategy suththere is no reinvestment risk over five years. Reinvestment risk will not occur if: I. Interest rates remain constant over the time periothe bon are hel II. The bon purchaseare callable. III. The bon purchaseare issuepar. IV. Only zero-coupon bon with a five-yematurity are purchase I only I anII only Ill only I anIV ANSWER: Reinvestment risk occurs when the intermeate coupon payments have to reinvestea rate thffers from the initirate. This es not happen if interest rates stconstant, or with zero-coupon bon. Callable bon ccalleearly, whicreates even more reinvestment risk for the principal. 为什么 interest rates stconstant就没有再投资风险？
IV、为什么only zero coupon bon对呢？每一期的COUPON都按照YTM投资，也没有reinvestment risk 啊
