This scatter plot visualizes the classic Iris dataset, plotting sepal width against sepal length for three species of iris flowers. Each flower is represented as a small circle, color-coded by species (setosa, versicolor, virginica) using a categorical color scale, with a legend in the upper right. The visualization uses D3 v3 to render an SVG graphic, employing `d3.scale.linear()` for the x and y axes, `d3.svg.axis()` for the axes, and `d3.scale.category10()` for coloring the dots. The data is loaded asynchronously from a tab-separated values file via `d3.tsv()`.