The management of Nebraska Corporation is considering the purchase of a new machine costing $490,000. The company's desired rate of return is 10%. The present value factors for $1 at compound interest of 10% for 1 through 5 years are 0.909, 0.826, 0.751, 0.683, and 0.621, respectively. In addition to the foregoing information, use the following data in determining the acceptability:

Year	Income from Operations		Net Cash Flow
1	$100,000		$180,000
2	40,000		120,000
3	40,000		100,000
4	10,000		90,000
5	10,000		120,000

The cash payback period for this investment is

a. 3 years

b. 4 years

c. 2 years

d. 5 years