This stacked bar chart visualizes the Iris dataset, showing the average measurements of sepal length, sepal width, petal length, and petal width for three Iris species: setosa, versicolor, and virginica. Using D3.js v7, the visualization applies `d3.stack()` to arrange the four numerical attributes as stacked segments within each species category. The code uses scale bands and linear scales for positioning, with color encoding via `d3.scaleOrdinal` and the Category10 color scheme. The resulting SVG provides a compact comparison of the relative contributions of each measurement type across species.