3. An investment cost $70,000 initially. In the first year it returned cash flows of $30,000, in the second year it returned cash flows of $15,000, in the third year $10,000, in the fourth year 5,000 and in the fifth and sixth year $12,000 per year. What is the cash payback period? a. b. C. d. PR e. 4 years. 4.8 years. 5 years. 5.8 years. 6 years