问题如下：
When the price of the underlying is below the exercise price, a put option is:
选项：
A. in-the-money.
B. at-the-money.
C. out-of-the-money.
解释：
A is correct.
When the price of the underlying is below the exercise price for a put, the option is said to be in-the-money. If the price of the underlying is the same as the exercise price, the put is at-the-money and if it is above the exercise price, the put is out-of-the money.
老师这个不是应该是 看跌期权 执行价格低于标的物才行权吗？