This interactive tree diagram displays a hierarchical classification of car types, branching from a root "Car Types" node into three transmission categories—Automatic, Manual, and Semi-Automatic—each with child nodes representing door counts. Built with d3.v7, the SVG visualization uses `d3.hierarchy` and `d3.tree` to compute node positions, then renders links with `d3.linkHorizontal` and nodes as circles with labels. The static dataset is hardcoded in the script, while an initial `d3.csv` call targets an external gist but its result remains unused.