the value in option 2, equipment upgrade is incorrect. Please explain the correct answer!

Nathan T Corporation is comparing two different options. Nathan T currently uses Option 1, with revenues of $81.000 per year, maintenance expenses of $6,200 per year, and operating expenses of $32,200 per year. Option 2 provides revenues of $74,000 per year, maintenance expenses of $6,200 per year, and operating expenses of $27,300 per year. Option 1 employs a piece of equipment which was upgraded 2 years ago at a cost of $21,000. If Option 2 is chosen, it will free up resources that will bring in an additional $5,000 of revenue. Complete the following table to show the change in income from choosing Option 2 versus Option 1. Designate Sunk costs with an "S" otherwise select "NA" (Enter negative amounts using either a negative sign preceding the number eg.-45 or parentheses e.g. (45).) Option 1 Option 2 Net Income Increase (Decrease) Sunk (5) Revenues $ 81000 $ 74000 $ -7000 NA A Maintenance expenses 6200 M 6200 i 0 NA Operating expenses 32200 27300 4900 NA Equipment upgrade 21000 21000 O S Opportunity cost 5000 0 5000 NA $ 2900