Which of the following is an assumption on which the argument depends? A. Prenatal exposure of mice to doses of BPA even smaller than those used in the experiment would not have significantly affected the physical development of the mice. B. At birth, there was no difference in size between offspring of mothers that had been given BPA and offspring of mothers in the control group. C. Postnatal exposure of mice to BPA before the mice are weaned has significant effects on the physical development of the mice. D. Exposure of a pregnant mouse to the doses of BPA used in the experiment does not significantly enhance its ability nurse its offspring. E. Significant differences in size between offspring of mothers that had been given BPA and offspring of mothers in the control group persisted long after the offspring were weaned.