This example shows the top 10 most populous countries as a horizontal bar chart. React manages the component state and SVG rendering, while D3 provides the scales and data loading. The chart maps country names to a `scaleBand` for the y-axis and population values to a `scaleLinear` for the x-axis. Ticks for both axes are manually generated using `xScale.ticks()` and the domain of the y-scale, with population data sourced from the United Nations World Population Prospects 2019 CSV via `d3.csv`.