Which of the following statements is incorrect?

a Retained earnings are irrelevant in calculating the WACC

b. Cash from net working capital (NWC) for each year is defined as NWC- NWC-1

C. Preferred equities are separate from common equities.

D. Sunk cost should not be included in the capital budgeting decision

E. Weights for equity in the WACC calculation are always based on market values