Nobel Tech Inc. is building a new production line. The cost of the production line is $3 million in the current year and $2 million in the following year. The production line is expected to bring in cash inflows of $1.6 million in year 2, and $2 million each year from year 3 to year 7. The company uses a cost of capital of 10% on all the projects.

The discounted payback period of this project is ____________.

Group of answer choices

a. 4.5 years

b. 6.5 years

c. 3.7 years

d. 5.5 years