This line chart visualizes petal length measurements from the Iris dataset, separating the data into three colored series by species: red for setosa, green for versicolor, and blue for virginica. Each point is plotted by sample index along the x-axis and petal length on the y-axis. The example demonstrates a reusable LineChart function built with D3 scales, axes, and a line generator, rendering to SVG. Data is loaded asynchronously via d3.csv from a GitHub gist.