问题如下：
Company A released its annual report to the public recently and its share price reacts gradually to it. With respect to efficient markets, which of the following statements about the market is correct?
选项：
A.The market is subject to behavioral biases.
B.The market is semi-strong-form efficient.
C.The market received additional information about the company.
解释：
C is correct.
The information from the annual report is already reflected in the stock prices if the markets are efficient. So the gradual changes of the stock prices are not to the releasing of annual report but to additional information.
所以我们判断市场有效性是用反映信息的“速度”，还是反映了“什么”信息？Assumption那个PPT里说，价格回归价值的速度反映市场有效的程度。所以虽然题目说的是gradually， 但最终还是反映了，所以我怎么觉得市场有效性介于semi-strong和strong中间？
