Given the question: As millions of playthings are recalled, doctors are reminded that the risks of lead exposure continue for young patients. Lead is such a well-known health - perhaps even contributing to the fall of the Roman Empire- that it came as a shock to discover that toys played by children could contain lead. Doctors are now dealing with the aftershocks. Just how dangerous is this exposure? That's the question physicians are being asked by parents who find a lead-polluted Elmo, of Dora. Millions of others toys, lunch boxes and pieces of jewelry manufactured in China have been recalled because they contain lead either in the paint that coats them or as a component of the plastic used to make the item more flexible. The lead content in some of the toys recalled this summer was 180 times the amount allowed by law. Some pieces of jewelry were almost 100% lead. Experts advise that the items do cause a risk and that doctors should urge parents to check the comprehensive lists of recalled products on the Consumer Product Safety Commission's Web site and return any appearing on those lists to the manufacturers. If exposure is suspected, a blood test is in order . Since there is no safe level of this universal element, the risk face by children for lead poisoning and its accompanying threat of learning disabilities and behavior problems is considerable. Doctors who have toys in their waiting rooms also are advised to see if any of them have been recalled and to check for chipped, flaking paint-even on those that haven't yet been recalled--since new announcements of toy risk continue. Why does the author mention "the fall of the Roman Empire"? A) To tell us a strange story. B) To warn us to keep away from lead. C) To explain why the Roman Empire fell. D) To show how terrible lead poisoning is.
The answer is:
D