Firm ABC is choosing its capital structure. The unlevered beta of the firm is 0.6. Market return is 9% and risk-free rate is 2% Tax rate is 37%. Which of the following three capital structure plan is the optimal plan (leads to lowest WACC) Debt 30% 50% 70% Cost of Debt Plan A Plan B Plan C Equity 70% 50% 30% 3.50% 4 00% 6.00% Plan A Plan O Plan C Not enough information