Every quarter, new information about the profits of companies is announced to the public. Researchers have found a phenomenon called post-earnings announcement drift. That is, companies with better(worse)-than-expected profit announcements not only have high (low) stock returns when the announcement is released but also continue to do so in the subsequent months. Therefore, a trading strategy that buys (sells) stocks with better(worse)-than-expected profit announcements can beat the market. Please choose the best answer from below.

(a) This does not violate market efficiency.

(b) This violates the weak form (and thus also the semi-strong and strong forms) of market efficiency.

(c) This violates the semi-strong form (and thus also the strong form) of market efficiency.

(d) This only violates the strong form of market efficiency