Which of the following statements is correct? A firm's weighted average cost of capital should decrease if its tax rate increases, but the yield to maturity of its noncallable bonds remains the same and all other factors are held constant. The cost of raising funds from retained earnings is usually a lot cheaper than the cost of debt financing, because the firm already possesses the funds in retained earnings If a firm wants to lower its cost of debt, it can simply issue debt with a lower coupon rate