A pie chart visualizes the distribution of car classes from a CSV dataset, showing the proportions of categories like 'unacc', 'acc', 'vgood', and 'good' as colored slices with percentage labels. The chart uses D3.js (version 7.8.5) with the `d3.pie`, `d3.arc`, and `d3.scaleOrdinal` APIs to compute and render the pie geometry and colors. A legend on the right lists each class with its count. The SVG is built programmatically, with data loaded asynchronously from a GitHub-hosted CSV file.