This pie chart visualizes the population of different countries using data loaded from a CSV file. The code renders SVG arcs with D3.js v3, using the `d3.layout.pie` and `d3.svg.arc` APIs to compute and draw each slice, with colors assigned via `d3.scale.category20`. A legend on the right lists each country name and its corresponding population value, while labels are placed at arc centroids using `arc.centroid`. The chart emphasizes the distribution of population across nations.