This visualization displays the distribution of iris flower measurements using a histogram with overlaid circles. The chart uses D3’s `scaleLinear`, `scaleOrdinal`, and `bin` functions to compute frequency counts, rendering bars and markers as SVG elements via React components. Data loads asynchronously from a CSV file through the custom `useData` hook, which parses numeric columns. Axes are generated with reusable `AxisBottom` and `AxisLeft` components, using D3’s tick generation and scale functions to position labels and lines.