A project requires an investment of $15,000 today and it is expected to generate after-tax cash flows of $3,000 per year for the next seven years. The company's weighted average cost of capital is 8.7% per year. What is the project's payback period? O 1) 3 years 2) 2 years 3) 4 years 4) 5 years 5) 6 years