study hub payback period question

Details of a new machine are as follows:

Capital cost $120,000
Expected operating life Five years
Expected scrap value at the end of five years $20,000
Annual depreciation $20,000
Expected annual profits from operations $40,000
5. What is the payback period?

A.3.0 years
B.2.5 years
C.2.0 years
D.1.7 years

The correct answer is C.

Payback = $(120,000 ÷ (20,000 + 40,000)) = 2.0 years

My answer:

3rd year since it is the year 3 when we reach the breakeven of 0 by calculating payback using the cumulative method. Please let me know how they arrived at he answer 2 years and not three years which we would arrive at if we calculate the cumulative .