Arnell Industries has $40 million in permanent debt outstanding. The firm will pay interest only on this debt. Arnell s marginal tax rate is expected to be 40% for the foreseeable future Suppose Arnell pays interest of 9% per year on its debt. What is its annual interest tax s b. What is the present value of the interest tax shield, assuming its risk is the same as the loan? c. Suppose instead the interest rate on the debt were 8%, what is the present value of the interest tax shield in this case