Choose the method of pay that would result in the most earnings for one month on sales of $40,000. a. Straight commission of 7.5% on all sales. b. Monthly salary of $1,600 plus 2.5% commission on all sales. c. Graduated commission of 5% on the first $30,000 in sales and 6% on anything over that. d. Graduated commission of 4% on the first $25,000 in sales and 8% on anything over that. Please select the best answer from the choices provided A B C D