问题如下：
Which of the following is most suitable to be seen as an example of a Bernoulli trial?
选项：
A. Estimating the probability that whether an investor will sell all his stocks or not
B. Determining the strike price of an option
C. Choosing one kind of fruit from apple, banana and watermelon
解释：
A is correct. A Bernoulli trial can only have two outcomes.
请问为什么是A，可否解释一下 谢谢