This example presents a dual-panel bar chart comparing BMI and height-weight data for individuals. The left panel shows a single bar per person representing BMI, while the right panel displays paired bars for height and weight. Data is loaded from a remote CSV file using `d3.csv`. The visualization uses `d3.scaleBand` for the categorical x-axis and `d3.scaleLinear` for the numeric y-axes, with axes rendered via `d3.axisBottom` and `d3.axisLeft`. The React component manages state with `useState` and `useEffect`, and output is rendered as SVG.