A firm's correctly computed capital structure consists of 20% debt, 10% preferred stock, and 70% equity. If new debt of $3 million can be raised at the current interest rate before a higher yield must be paid to investors, at what point will the MCC break upward because of the cost of debt? a. $3,000,000 b. $10,000,000 c. $15,000,000 d. none of the above