explain

Let Bu denote the unlevered beta of a firm with debt D and equity E. Assume that the tax rate is t. According to the CAPM, the cost of equity of a firm is given by: A) By the equity risk premium, RM - Ry B) By the yield of the bonds of the firm C) By the weighted average cost of capital (WACC) D) Ry + Bu(RM R) E) R+(1+(1 t)) Bu(RM Ri) 1