Assume that capital markets are perfect. A firm finances its operations via $60 million in stock with a required return of 15% and $40 million in bonds at 8%. Assume the company decides to issue an additional $10 million in bonds and use the proceeds to retire $10 million worth of equity, (a) what would happen to the firms WACC? (5 points) (b) What would happen to the required return on the companys stock? (5 points)

The questions I see posted on here state the WACC does not change, however it is not explained why and I keep getting that it does