C选项少了一个long bond吧

问题如下：

Which of the following statements is most likely correct?

选项：

Volatility has significant effect on put-call parity.

According to put-call parity, the put price equals call price.

According to put-call-forward parity, a fiduciary call is equivalent to a protective put with a forward contract.

解释：

C is correct. put-call-forward parity:

$\frac{{\text{F}}_0(\text{T})}{{(1+r)}^\text{T}}+p_0=c_0+\frac{\text{X}}{{(1+r)}^\text{T }}$

A is incorrect, volatility has no effect on put-call parity

中文解析：

波动率对put-call parity没有影响；

put-call forward parity 是put-call parity的一个扩展，put-call parity：C+K=P+S，其中等式右边的 long stock = long forward + long bond,bond 的面值为F0(T)

注意等式左边的bond的面值为X，

0时刻便有等式：