notes上的一道练习题:
A decrease in the risk-free rate of interest will:
A: increase put & call prices.
B: decrease put prices & increase call prices.
C: increase put prices & decrease call prices.
答案是C,有人可以给个解释吗?risk free interest rate为什么和put price成反向关系和call price成正向关系呢?谢谢啦!