A choropleth map of the world displays national life expectancy in 2015, with a quantized color scale shading countries from pale lavender to deep purple based on their average lifespan. The visualization loads country boundaries from a GeoJSON file and life expectancy data from a CSV using D3 v7, projecting geographic coordinates with `d3.geoMercator` and rendering paths via `d3.geoPath`. A hover interaction changes the fill color of individual countries, while the underlying data originates from the World Health Organization via Kaggle.