A world map shows total COVID-19 cases on May 31, 2020, for ten selected countries. Red circles sized with a square-root scale (`d3.scaleSqrt`) represent case counts, while `d3.geoNaturalEarth1` and `d3.geoPath` render the sphere, graticules, landmasses, and country borders. Data from a CSV file is filtered by month and date, then merged with coordinates. The visualization is built with React, D3 v5, and TopoJSON, rendering marks as SVG circles with hover titles showing country names and totals.