This visualization displays a pie chart of worldwide COVID-19 cases for 2020, highlighting the top 15 countries by reported case counts. The chart uses a legend with colored rectangles and text labels to identify each country alongside its corresponding number of cases. Built with React and D3 v5, the code employs `d3.csv`, `d3.pie`, `d3.arc`, and `d3.scaleOrdinal` with a `schemeCategory10` color palette to render the SVG-based chart. Data is loaded from a gist-hosted CSV file, sorted descending by case numbers, and sliced to show only the leading countries.