Yancy is considering a project which will produce cash inflows of $900 a year for 4 years. The project has a 9% required rate of return and an initial cost of $2,800. What is the discounted payback period?

A. 3.11 years B. 3.18 years C. 3.82 years D. 4.18 years E. never

I know the answer is C, but I need a clear explaination on how to get to that answer.