The efficient market hypothesis suggest that Stock prices tend to follow a " random walk " . Thus, the best strategy for investing is : A) a " buy and hold " strategy on to stock until you badly need the money B) turning over your stock portfolio each week, selecting stocks by throwing darts at the stock page C) a " churning strategy" of buying and selling often to catch market swings. D) a " buy and hold strategy" of holding on to stocks to avoid brokerage commissions