The management of Wyoming Corporation is considering the purchase of a new machine costing $375,000. The company's desired rate of return is 6%. The present value factor for an annuity of $1 at interest of 6% for 5 years is 4.212. In addition to the foregoing information, use the following data in determining the acceptability of this investment:

Year	Operating Income		Net Cash Flow
1	$18,750		$93,750
2	18,750		93,750
3	18,750		93,750
4	18,750		93,750
5	18,750		93,750

The cash payback period for this investment is

a. 4 years

b. 20 years

c. 5 years

d. 3 years