Which of the following statements are true.

I. The Miller-Orr and Baumol models both consider transactions costs

II. The Miller-Orr and Baumol models both allow for variance of cash flows.

III. The Miller-Orr and Baumol models allow for opportunity costs.

a. I and III

b. I and II

c. I, II, and III

d. II only

e. II and III