D is correct.
Federal law prohibits employment agencies from discriminating against their own employees as well as in their referral practices. It was illegal for the employment agency to refer only Samantha to the law firm if Andrew was also qualified for the receptionist job. If Andrew filed a charge of discrimination with EEOC, in addition to determining whether the employment agency discriminated against Andrew, EEOC would also determine whether the law firm asked the employment agency to only refer women for the position.
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