单选题 In 2005 scientists in Spain reported that the more pesticides children were exposed to as fetuses (胚胎), the greater their risk of being overweight as toddlers. And last January scientists in Belgium found that children exposed to higher levels of PCBs and DDE ( the breakdown product of the pesticide DDT) before birth were fatter than those exposed to lower levels. Neither study proves causation, but they "support the findings in experimental animals," says Newbold. They "show a link between exposure to environmental chemicals...and the development of obesity. "
In the paragraph the writer intends to convey to the reader that

• A. there might be a link between exposure to environmental chemicals and the development of obesity.
• B. there is a cause - effect relation between exposure to environmental chemicals and obesity.
• C. children who are exposed to pesticides are likely to develop obesity in their adulthood.
• D. scientists have done experiments to see the link between environmental chemicals and obesity for years.