A company's weighted average cost of capital is 11.3% per year. A project requires an investment of exist20,000 today and it will generate after-tax cash flows of exist10,000 at the end of year 1, exist5,000 at the end of year 2, exist5,000 at the end of year 3, and exist3,000 at the end of year 4. What is the project's payback period? 3 years 4 years 6 years 5 years 2 years