This D3 scatter plot visualizes the classic Iris dataset, mapping petal length and sepal width for 150 flowers to SVG circles. It demonstrates the modern d3.select API and the new d3.scaleLinear with extent helper, using d3.csv for data loading, d3.axisLeft and d3.axisBottom for axes, and a direct selectAll and join pattern to bind data to circles. The chart fills the browser viewport and employs consistent 20px tick labels for readability.