Under most civil service systems, concerning involuntary termination of employment by layoff: Select one: a. Layoffs must be made on the basis of job classifications, not individual employees. b. For the most part, seniority and performance evaluation ratings are irrelevant in determining who will be laid off. c. More senior employees have the right to "bump" employees of lesser seniority throughout the organization. d. Managers above the level of first-line supervisor are immune to layoff