Which one of the following statements is true?

A. Even if weak form market efficiency is true, it does not mean that studying charts of past prices and searching for repeating pattern is useless.

B. Even if the semi-strong version of the efficient market hypothesis is true, it might be possible to earn extraordinary returns from private information not available to other investors.

C. If stock prices move randomly, charting and technical analysis are useful investment tools.

D. If a company's revenues and earnings are highly predictable, it's stock price will also be highly predictable.