Ask yourself: "What comparison is the audience making?" Then choose the chart that makes that comparison obvious.
Strong answers match chart type to data relationship: bar charts for comparison, line charts for trends over time, scatter plots for correlation, histograms for distribution. They should mention when pie charts are misleading (too many slices, similar sizes), when dual-axis charts distort, and the importance of labelling and context.
Tests communication and visual literacy. The best analysts obsess over whether their chart tells the right story. Red flag: defaulting to the same chart type for everything.