An interactive D3.js bar chart displays CO₂ per capita for countries in 2023, with buttons reordering bars alphabetically, by value, or by a derived attribute. The chart is part of a homework assignment that also generates static SVG screenshots comparing stacked bars, a reordered matrix, a radial layout, and parallel coordinates, all built with D3 v7 and a reusable bar-chart closure. Data comes from a remote CSV file.