This example shows a choropleth-style map of Mexico’s twelve regions rendered with D3 and React, using a dropdown menu to select a region. TopoJSON data from ArcGIS is loaded via d3.json, converted to GeoJSON with topojson.feature, and drawn as SVG paths using d3.geoPath with a Mercator projection. The map includes graticules and white state boundaries, with the selection state tracked in React and passed to the Dropdown component.