A salesperson is offered the following compensation methods for one month: (A) a fixed salary of $2,500, (B) a 5% commission on net sales, (C) a $1,000 salary plus a 3% commission on net sales, and (D) a $2,000 salary plus a 2% commission on net sales. If net sales for the month are $40,000, which method will result in the highest earnings?