Assume that the risk-free rate is 5 percent. Which of the following statements is most correct? a. If a stock's beta doubles, the stock's required return will also double. b. If a stock's beta is less than 1.0, the stock's required return is less than 5 percent. All of the statements above are correct. If a stock has a negative beta, the stock's required return is less than 5 percent. d