The information in paragraph three does discuss the effects of chronic stress and points out that there is a link between stress and "health effects far from the brain" (including preterm birth). The paragraph then cites data on African-American and white preterm birth rates. Rather than explain a definitive, causal link, the paragraph then jumps into a hypothesis that explains the data. The use of "hypothesis" and "posits" are clues that any link we make between the data points is an extrapolation. It's definitely suggested by the data, but we can't say definitively that it is the case.I do not understand how the information in Paragraph 3 was not enough to validate RN II. If the statement said that "African American mothers are more likely to have elevated cortisol levels than white mothers," would this be correct?
I hope this helps and thanks for your question!