Suppose the universe of possible investments consists of a risk-free asset paying 2% and the following four portfolios: Portfolio Expected return Standard deviation A 10% 20% B 12% 24% C 14% 27% D 16% 33% For an investor who can invest in both the risk-free asset and a risky portfolio and who has a high tolerance for risk, which of the four risky portfolios is preferred? What about for an investor with a very low tolerance for risk? Explain.