Which of the following statements is FALSE?

a. The WACC method can be used to evaluate a new project if the new project has a similar level of risk compared to the rest of the firm. b. Firms with lower tax rates always have higher WACC. c. After a firm finds a positive NPV project using the WACC method, one way to keep the debt-equity ratio constant is by borrowing more debts. d. In the WACC method, we value a project based on its free cash flow, which is computed by ignoring interest and debt payments.