Task: Question Generation
Input (English): Background Paragraph: Many chemicals that were once commonly used were later found out to be harmful to the environment , to human health, or both. The element lead was once a common additive to gasoline and to paint. Plumbing pipes were once typically made of lead. Only since the 1970s has the danger of lead become apparent. It causes brain damage and small children (who often chewed on objects painted with lead-based paint) are particularly susceptible. The use of lead in gasoline, paint, and plumbing pipes is now banned and new materials are being developed to replace the hazardous lead components. 
Story: John is trying to buy a house. Today, he saw two houses, house A and house B. House A was build in the 1920s. It has lead plumbing pipes and lead based paint. House B was build recently. It does not have lead plumbing pipes or lead based paint.
Output (English): Which house most likely used newly developed materials, house A or house B?