This pie chart visualizes BMW car sales distribution by model, with each slice showing the total sales volume for a specific model. The chart renders as SVG using D3.js, with labels positioned around the outer arc showing each category’s percentage share. Data comes from a CSV file loaded via `d3.csv`, aggregated with `d3.rollup`, and visualized using `d3.pie` and `d3.arc`. A color legend and interactive tooltips are also included.