A line chart tracks cumulative COVID-19 deaths over time, plotted with a linear y-axis. The chart uses `scaleTime` and `scaleLinear` from D3 v5 via React components, rendering to SVG. Data is fetched from the Johns Hopkins Coronavirus Dataset as CSV, with the `csv` loader summing daily totals per country. X and Y axes use `axisBottom` and `axisLeft`, with grid lines via `tickSize`, though marker-line components are defined but not rendered.