Cosmo has a weighted average cost of capital of 6.45%. Estimate Cosmo's cost of equity given the following information: The firm's effective tax rate is 25%, they have an equal mix of debt and equity, the required return on the market portfolio is 9%, Cosmo has a before-tax cost of debt of 6%, and the risk-free rate of return is 3%. 10.50% 8.40% 9.60% 9.90%