The appropriate measure for risk according to the capital asset pricing model is the standard deviation of a firm's cash flows. alpha. the standard deviation of a firm's stock returns. beta QUESTION 21 If the beta for stock A equals zero, then stock A's required return is equal to the required return on the market portfollo stock A's required return is equal to the risk-free rate of return stock A has a guaranteed return. stock A's required return is greater than the required return on the market portfolio