4) Which of the following statements is CORRECT? (Note: a thought-provoking conceptual question!) a. When calculating the cost of preferred stock, a company needs to adjust for taxes, because preferred stock dividends are deductible by the paying corporation. b. All else equal, an increase in a company's stock price will increase its marginal cost of retained earnings, rs. (hint: think of the DCF approach: Equation 9-9) c. All else equal, an increase in a company's stock price will increase its marginal cost of new common equity, re. (hint: think of the DCF approach: Equation 9.9 or Equation 9.12) d. Since the money is readily available, the after-tax cost of retained earnings is usually much lower than the after-tax cost of debt. e. If a company's tax rate increases but the YTM on its noncallable bonds remains the same, the after-tax cost of its debt will fall. (hint: Equation 9.2)