ZZ$$s Fashion, a small online clothing retailer operating only in Gauteng, is considering buying a new forklift to boost productivity in their distribution facility. The owner indicated that, if the payback period for the forklift is less than $4$ years, ZZ$$s credit provider will supply credit for the purchase. If the payback period is calculated as: Payback $=$ machine cost $/$ Y$,$ then Y represents $...$

net cash flow after operating costs, excluding interest charges on the capital loan.

annual interest repayment, excluding other operating expenses.

net cash flow before depreciation deductions.

net cash flow after operating costs, depreciation and interest charges have been deducted.