A profit-maximizing monopsonist hires both men and women to do a certain task. The two sexes are equally good at this task and are regarded as perfect substitutes. Labor supply curves for both sexes are upward-sloping. In order to hire M men, the firm would have to pay men a wage of AM, where A is a positive constant. In order to hire F women, the monopsonist would have to pay a wage of BF c where B and c are positive constants. Which, if any, of these conditions necessarily implies that he pays a lower wage to women than to men?