9. (4 points) Which of the following is/are truth?

(a) A portfolio with low alpha and low tracking error is preferred.

(b) A portfolio with low alpha and high tracking error is preferred.

(c) A portfolio with high alpha and low tracking error is preferred.

(d) A portfolio with high alpha and high tracking error is preferred.

(e) It depends on investors risk tolerance.

(f) All of the above