This pie chart visualizes population distribution by age group, with slices labeled and a color-coded legend for reference. The data is loaded from a remote CSV file via `d3.csv`, and the chart is rendered using `d3.pie` to compute arc segments, `d3.arc` for path geometry, and `d3.scaleOrdinal` with a category color scheme. Labels are positioned at each arc’s centroid, and the SVG output uses a `d3.select`-based join to append paths and text elements dynamically.