Which of the Following Statements Is False

Which of the following statements is false?

A) If the CAPM correctly computed the risk premium, investors would stop investing only when they expected the alpha of an investment strategy to be negative.
B) If the CAPM correctly computes the risk premium, an investment opportunity with a positive alpha is a positive-NPV investment opportunity.
C) If the CAPM correctly computes the risk premium, investors should flock to invest in positive alpha stocks.
D) Anyone can implement a momentum trading strategy and therefore generate a positive investment opportunity.