Alloys (copper-based): Which metals constitute gunmetal (traditional composition)? Think of the bronze used historically for guns/valves/bearings. Choose the correct ingredient set.

Given data

• Alloy: Gunmetal (a bronze).

Concept/Approach Traditional gunmetal is a copper–tin bronze (often with a small percentage of zinc/lead in modern specs). Among the options given, the correct core constituents are copper and tin.

Final Answer Copper, Tin