If the optimal amount of debt for a firm is positive, then A. direct financial distress costs must equal the present value of the interest tax shield. B. the value of this levered firm must exceed the value of the unlevered firm with the same assets. C. value of the firm is minimized. D. value of the firm is equal to unlevered firm value plus interest tax shield benefits. E. debt-equity ratio is equal to 1.0. If the optimal amount of debt for a firm is positive, then A. direct financial distress costs must equal the present value of the interest tax shield. B. the value of this levered firm must exceed the value of the unlevered firm with the same assets. C. value of the firm is minimized. D. value of the firm is equal to unlevered firm value plus interest tax shield benefits. E. debt-equity ratio is equal to 1.0