The verified response to “Ancient History question: Which alloy was commonly used by the Harappans?” is Bronze, option D. The original question-specific evidence states: Bronze was the principal alloy used in Harappan metallurgy. Bronze is the correct answer to “Which alloy was commonly used by the Harappans”. This evidence connects the required Ancient History fact with its archaeological, geographical, cultural or chronological setting. The choices Steel, Brass and Aluminium do not satisfy the same combination of site, feature, river region, crop, craft, discovery, chronology or cultural association. Replaying that method confirms Bronze as the keyed response for this Ancient History question.