Question does not provide a discount rate

This all the information the question provides

7. A project requires $1000 to be invested today, and is expects to generate cash flows in the future years: CF1-5500, CF2=$400, CF3-$200. What is the discounted payback period of this project? a) 2.5 years b) 3 years c) 1.25 years d) None of the above e) Never pay back the cost