which letter is incorrect

5. Everyone should make sure that they are well represented in union meetings : B otherwise, management could become too powerful. D 6. The employment agency, too busy to return the telephone calls from prospective AB clients, are harming business opportunities. CD 7. The supervisory staff are making decisions based on scheduling, but all employees A B want to ensure quality control. D 8. Because the price of cars has risen dramatically most people keep A their cars longer to save capital expenditures. B C D