Which of the following statements is correct? Group of answer choices Personnel systems based on merit are those where personnel decisions are based on seniority or politics. Unions prefer to negotiate wages for their workers and see individual incentive or merit plans as ways of pitting one union member against another and introducing conditions in which managers can favor one employee over another. Supervisors never need to evaluate performance of volunteers. From the perspective of public sector agencies, performance evaluation systems are more critical to those employed by an outside contractor than for agency employees