Followers of the efficient market hypothesis believe thata) very few investors actually analyze or evaluate stocks before they make a purchase decision. b) the needed information to assess the market is available only to corporate insiders. c) investors react quickly and accurately to new information. d) individual traders can have a significant impact on the price of a security.

Followers of the efficient market hypothesis believe that "C) investors react quickly and accurately to new information.".

Explanation: The efficient market hypothesis states that the current price of an asset in the market reflects all available information that exists (historical, public and private). It considers that any news or future event that may affect the price of an asset, will make the price adjust so quickly, that it is impossible to obtain an economic benefit from it.

This adjustment happens so fast because investors act quickly and accurately in the face of new information.