NO.PZ2018062007000035
问题如下：
If the underlying price is below the exercise price at expiration, the value of a European call option will be:
选项：
A.positive
B.negative
C.zero
解释：
C is correct.
If the underlying price is below the exercise price at expiration, the holder would just let the call expire rather than exercise, so the option is worth nothing. The minimum value of option is zero.
如果标的资产价格在到期日低于执行价格，那么call的持有者不会行权，期权价值为0。
低于行权价格不是应该行权吗？就可以以更高的价格实现
