Identify a provision of Section 503 of the Vocational Rehabilitation Act of 1973. Multiple choice question. It mandates federal taxes to be paid by all employers and employees based on wages received in employment for any service performed. It requires employees to receive an allowance, called an employment and support allowance, from their employers. It requires old-age benefits to be paid to all employees based on wages received in employment in any service performed within the United States. It requires affirmative action on the part of federal contractors and agencies to recruit, hire, and train disabled workers