A line chart tracks cumulative COVID-19 deaths over time, with a dashed marker line at 10,000 deaths and a second marker at the most recent date. The React component uses d3.scaleTime, d3.scaleLinear, and d3.line to generate an SVG path from CSV data. d3.axisBottom renders the x-axis with tick lines, while custom XMarkerLine and YMarkerLine components add annotations. The data comes from the Johns Hopkins CSSE COVID-19 time series.