问题
单项选择题
If a firm announces an unexpectedly large cash dividend, the efficient market hypothesis (EMH) would predict which of the following price changes at the announcement（）
A. An abnormal price change to occur before the announcement.
B. An abnormal price change to occur at the time of the announcement.
C. A gradual price change to occur for several weeks after the announcement.
答案
参考答案：B
解析：
Market efficiency assumes investors adjust their estimate of security prices rapidly to reflect their interpretation of the new information received. Market efficiency also assumes that new information comes to market randomly and is available to all investors at the same time. Therefore, the price should not be reflected prior to the announcement.