A firm's overall cost of equity is: I affected by changes in the market risk premium. II. inversely related to changes in the firm's tax rate. III. generally equal to the firm's WACC for a levered firm: IV. generally lower than the firm's after-tax cost of debt. V. independent upon the growth rate and risk level of the firm. Multiple Choice o 1only o only I only Ill only V only Ill and V only 1. IV and V only