The discovery of a scale, stone weights, and a marked rod suggests that the people of Mohenjodaro A. had uniform ways to measure. B. knew how to make tools of iron. C. traded with people from far away. D. started a new kind of mathematics.

The discovery of standardized weights and measures in Mohenjodaro indicates that these ancient people had developed a sophisticated understanding of trade and commerce. Such tools were essential for fair trading practices, allowing merchants to assess the value of goods accurately. This hints at a well-organized economy where trade wasn't just a barter of goods but involved precise calculations. Additionally, the existence of a marked rod implies that the society had concepts of measurement that extended beyond simple weight. It suggests an early form of mathematics was in play, enabling them to undertake complex agricultural and architectural projects. This advancement laid the groundwork for measuring land and resources, showcasing their intellectual progress and organizational skills.