Jose rents office space for​ $20,000 per year. He uses the office to fill out tax returns for​ 1,000 clients per year. If the office rent increases to​ $25,000 per​ year, the marginal cost of filling out tax returns will A. ​increase, but we cannot determine the amount of the increase with the information given. B. increase by​ $5. C. not change. D. increase by​ $5,000.