问题如下：
A stock is priced at $100.00 and follows a one-period binomial process with an up move that equals 1.05 and a down move that equals 0.97. If 1 million Bernoulli trials are conducted, and the average terminal stock price is $102.00, the probability of an up move (p) is closest to:
选项：
A.0.375.
B.0.500.
C.0.625.
解释：
C is correct.
The probability of an up move (p) can be found by solving the equation: (p)uS + (1 – p)dS = (p)105 + (1 – p)97 = 102. Solving for p gives 8p = 5, so that p = 0.625.
老师您好，我看了其他同学提问下的回答，“二叉树假设下一期只有两种情况，要么股价上涨为Su（即答案解析公式中的uS），概率为P；要么股价下跌为Sd（即答案解析中dS）”对于这一句我有点疑惑，题目中说的是 with up move 1.05 and down move 0.97,所以我理解的是这个down move 0.97是在up move 1.05 下的一个分支，请问为什么不是我这么理解呢 如果按老师说的那题目不应该是Or down move 0.97吗 ，不好意思老师们呜呜呜我老有这种奇奇怪怪的问题
