单选题 Which of the following is least likely to be one of the assumptions that underlie an efficient capital market?

A、 Expected returns include risk in the price of the security.
B、 A large number of profit-maximizing participants are analyzing and valuing securities independent of each other.
C、 Investor adjust their estimates of security prices slowly to reflect their interpretation of the new information received.

【正确答案】 C

【答案解析】[解析] 有效资本市场理论基于以下假设：
(1)市场中存在大量以利润最大化为目标的参与者，这些参与者相互独立地对证券进行分析和估价。
(2)最新信息随机地出现在市场中，最新信息的宣布在时间上相互独立。
(3)投资者根据其对最新信息的理解，快速地对证券价格的预期作出调整。
(4)证券的预期回报率中包含由证券价格变动所带来的风险因素。
由上述内容可知，选项c的内容不符合有效资本市场理论的相关假设。