According to the article, what valid claim came from the national research council?

The National Research Council (NRC) is an American nonprofit, non-governmental organization. The National Research Council is the research arm of the National Academies of Sciences, Engineering, and Medicine, which includes the National Academy of Sciences (NAS), the National Academy of Engineering (NAE), and the National Academy of Medicine (NAM).

The National Research Council produces reports that shape policies, inform public opinion, and advance the pursuit of science, engineering, and medicine. It is the research arm, but not member of the National Academies of Sciences, Engineering, and Medicine, unlike the National Academy of Sciences, the National Academy of Engineering, and the National Academy of Medicine.