Metal building materials commonly used include ___ _____, steel, aluminum and copper.

• A. Bronze
• B. Cast Iron
• C. Lead
• D. Tin

Answer: (B)

Cast iron completes the list. In building, iron and its derivatives appear alongside steel, aluminum, and copper as commonly used metals, especially for components like pipes and radiators. Cast iron is strong in compression and has been a staple in construction for many years, even though modern structural work relies heavily on steel. Bronze, lead, and tin are less typical as primary building materials—bronze is mainly decorative hardware, lead is heavy and toxic, and tin is usually used for coatings or solder. Cast iron fits naturally as the two-word material in the blank.