This horizontal bar chart displays the populations of 20 countries in 2010, sorted by country name along the y-axis. Each bar’s length encodes population value, with a formatted tick label converting SI units (e.g., "B" for billions) for readability. Built with React and D3 v5, it uses `scaleBand` for the categorical y-axis, `scaleLinear` for the continuous x-axis, and renders SVG rectangles via the `Marks` component. Data is loaded asynchronously from a CSV file using `d3.csv`, then sliced to the first 20 rows.