Honor cube corporation currently has a debt-equity ratio of 0.70, an after-tax cost of debt of 7.5%, and a cost of equity of 14%. If the firm changes its debt-equity ratio to 0.40, it will

a) Decrease the firms weighted average cost of capital

b) Cause the NPV of projects under consideration to decrease

c) Increase firms total debt

d) Not have an effect on the firms capital budgeting decisions