The capital asset pricing model (CAPM) assumes which of the following?
I. a risk-free asset has no systematic risk.
II. beta is a reliable estimate of total risk.
III. the reward-to-risk ratio is constant.
IV. the market rate of return can be approximated.
A. I and III only
B. II and IV only
C. I, III, and IV only
D. II, III, and IV only
E. I, II, III, and IV