This stacked bar chart visualizes the Iris dataset, showing the average measurements of sepal length, sepal width, petal length, and petal width for each of the three iris species. The code uses d3.csv to load the data, d3.stack to group the four numeric attributes into layers, and d3.scaleBand and d3.scaleLinear to map species and cumulative values. Rendered as SVG, each colored segment represents one measurement category, with axes added via d3.axisBottom and d3.axisLeft.