Which of the Following Statements Concerning Beta Are Correct

Which of the following statements concerning beta are correct?
I. Adding stocks with high betas to a portfolio increases the portfolio's risk.
II. The higher the beta, the higher the expected return.
III. A beta can be positive, negative, or equal to zero.
IV. A beta of .35 indicates a lower rate of risk than a beta of -0.50.

A) II and III only
B) I and IV only
C) II, III and IV only
D) I, II, III and IV