Colonna & Co needs to raise $50 million for its invention. It can raise debt at a rate of 8 percent. Colonna pays taxes at a 40% rate. Investors require a 10 percent return on its common stock, and investors currently yield 9 percent when investing in their preferred stock. Given that Colonna plans to raise this money using $25 million of common stock and $5 million of preferred stock; and the remainder in debt; what is the company's WACC? a. 7.82% b. 5.90% c. 9.00% d. 4.15% e. 9.10%