Which of the following statements is most correct?

a. An increase in expected inflation could be expected to increase the required return on a riskless asset and on an average stock by the same amount, other things held constant.

b. The CAPM has been thoroughly tested, and the theory has been confirmed beyond any reasonable doubt.

c. If two "normal" or "typical" stocks were combined to form a 2-stock portfolio, the portfolio's expected return would be a weighted average of the stocks' expected returns, but the portfolio's standard deviation would probably be greater than the average of the stocks' standard deviations.

d. If investors became more risk averse, then (1) the slope of the SML would increase and (2) the required rate of return on low-beta stocks would increase by more than the required return on high-beta stocks.

e. A graph of the SML would show required rates of return on the vertical axis and standard deviations of returns on the horizontal axis.