问题如下：
Based on Exhibits 1 and 2, the probability that Njau will be able to meet her charitable goal is closest to:
选项：
A.25%.
B.50%.
C.75%.
解释：
B is correct. The Monte Carlo simulation shows that Njau has a 50% probability of having an amount exceeding $553,803 in Year 15. Since Njau’s charitable pledge goal to Udhamini is $500,000, she has a slightly greater than 50% probability of meeting or exceeding her charitable pledge goal in Year 15.
不理解，为什么不是75%
