Final answer:
The federal law with the largest jurisdiction in terms of the number of employers required to follow its provisions is the Age Discrimination in Employment Act (ADEA). It prohibits age discrimination in employment for employers with 20 or more employees.
Step-by-step explanation:
The federal law or regulation with the largest jurisdiction as it relates to the number of employers required to follow its provisions is the Age Discrimination in Employment Act (ADEA). This act, passed in 1967, prohibits employers from discriminating against individuals aged 40 and over in any aspect of employment, including hiring, firing, promotions, wages, and benefits. It applies to employers with 20 or more employees and also covers labor organizations, employment agencies, and the federal government.
Other laws and regulations, like Executive Order 11246, Rehabilitation Act, and the Vietnam Era Veterans Readjustment Assistance Act, have more specific jurisdictions and requirements. For example, Executive Order 11246 enforces equal employment opportunities for federal contractors and subcontractors, while the Rehabilitation Act prohibits disability discrimination in federal employment and programs receiving federal funds. The Vietnam Era Veterans Readjustment Assistance Act focuses on protecting veterans from discrimination in employment.