Which of the following statements about the risk-return trade off is true?

a. If an investor is a risk lover, the investment attractiveness increases with expected return and decreases with risk.

b. Assuming the return is normally distributed with a postive mean and variance, the probability of an investment loss is larger in the long run.

c. Sharpe ratio measures the risk premium for one unit of total risk.

d. Portfolio A dominates portfolio B if porfolio A has a smaller variance than portfolio B.

e. Portfolio A dominates portfolio B if porfolio A has a higher expected return than portfolio B.