If an investor is averse to risk, then the following statements are true: (4 good answers) a) He/She never takes any risks; b) He/She requires a risk premium which is positive; c) He/She prefers investments whose expected returns are the highest ones for a given risk; d) He/She prefers investments whose risks are the lowest ones whatever are their expected return; e) His/Her utility function is a concave function. f) If a risky investment provides the same expected return as