This interactive D3.js visualization displays COVID-19 metrics over time for selected countries, allowing viewers to toggle between confirmed cases, deaths, and recoveries via two dropdown menus. The line chart uses a time-based x-axis and a linear y-axis, with a single red, blue, or green line rendered per selection. Data is loaded from a CSV file, processed by nesting and grouping entries by date, and filtered by country. The visualization uses D3's `scaleTime`, `scaleLinear`, `axisBottom`, `axisLeft`, and `line` with `curveBasis` for smooth curves.