solve question 3 please.

3. Navarro Corp. has no debt but can borrow at 5.9 percent. The firm's WACC is currently 9.20 percent, and the tax rate is 21 percent. a. What is the company's cost of equity? b. If the company decides to raise $10 million perpetual debt and converts to 25 percent debt (of the levered firm value), what will its cost of equity be? Is your answer consistent with Modigliani-Miller's proposition? Why? c. What are the firm values before and after the company raised the debt? d. What is the company's WACC in part (a)? In part (b)