Which of the following is FALSE? a. Risk-averse investors require higher rates of return on investments whose returns are highly uncertain, and most investors are risk averse. b. The realized return on a stock portfolio is the weighted average of the expected returns on the stocks in the portfolio. c. According to the Capital Asset Pricing Model (CAPM), the relevant risk of a stock is the stock's contribution to the riskiness of a well- diversified portfolio. d. "Risk aversion" implies that investors require higher returns on riskier than on less risky securities