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

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

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

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

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