7. Zhou Fang and Company has just purchased a new piece of equipment, the cost characteristics of which are given below: Purchase cost when new. $30,000 Annual cost savings. $6,000 Salvage value. Donnell $0 Life of the equipment. 15 years The Company uses a required rate of return of 10% and depreciates equipment using the straight- line method. The payback period for the investment is: A 5 years B. 15 years C. 2 years D. 7.143 years