A React-based bar chart displays United Nations population projections for 2020 across 15 countries, using an SVG rendering with D3 v5 scales. The visualization pairs a linear x-axis from `d3.scaleLinear` with tick marks generated by `xScale.ticks()`, and a band y-axis from `d3.scaleBand` labeling countries. The `AxisBottom` and `AxisLeft` components render grid lines and text labels, while `Marks` draws the proportional rectangles. Data loads asynchronously from a CSV using `d3.csv`.