This example shows the distribution of car classes as a simple pie chart, with each slice labeled by its category name and percentage of the total. It loads a CSV file using `d3.csv`, aggregates class counts with a `reduce` operation, and renders the chart with D3’s `d3.pie` and `d3.arc` methods on an SVG. A categorical color scale (`d3.scaleOrdinal`) assigns colors from `schemeCategory10`, and labels are positioned using the arc centroid calculation while the slice area is scaled by the outer radius.