问题如下：
In light of recent poor employment figures and two consecutive quarters of negative GDP growth, the consensus forecast among economists is that the central bank, at its next meeting this month, will take actions that will lead to lower interest rates.
Exhibit below shows four fixed-rate investment-grade bonds issued by Alpha Corporation which are being considered for investment.
Note: All bonds in Exhibit 2 have remaining maturities of exactly three years
Assuming the forecast for interest rates is proven accurate, which bond in Exhibit above will likely experience the smallest price increase?
选项：
A.Bond 1
B.Bond 3
C.Bond 4
解释：
C is correct.
考点：考察对含权债券的理解
解析 ： 经济预测是利率下降 。 在利率下降的环境中 ， 任何债券的价值都应该上升 ， 只不过当利率下降时 ， 不同含权债券的表现不同 。
当利率下降时 ， 债券4 （ Callable ） 中的Embedded call option的价值会增加 ， 由于该期权为发行人持有的期权 ， 因此Embedded option价值的上升会对Callable bond的价格产生相反的影响 ， 会抵消掉部分利率上升带来的债券价格上涨 。 因此Callable bond在利率下降时 ， 上升的幅度最小。
老师请问，利率下降，bond price上升不就使得callable bond更容易被执行吗？所以callable bond price更值钱？利率不是影响callable bond和putable bond的整体value吗？不是单纯的call option和put option吧？就是影响下面两个等式的左边：
Vcallable bond=Vstraight bond-Vcall
Vputable bond=Vstraight bond+Vput
