That woman’s physical structure and the performance of maternal functions place her at a disadvantage in the struggle for subsistence is obvious. . . . [C]ontinuance for a long time on her feet at work . . . tends to injurious [harmful] effects upon the body, and, as healthy mothers are essential to vigorous offspring, the physical well-being of woman becomes an object of public interest and care in order to preserve the strength and vigor of the race. —Muller v. Oregon, 1908

Which BEST explains one negative effect of the Muller decision?