This line chart displays the population of five selected countries—India, the United States, China, Japan, and Germany—from 2011 to 2021. It loads comma-separated data via `d3.text`, parses it, and renders multiple lines using `d3.line` with `d3.curveLinear`. Axes are generated with `d3.axisBottom` and `d3.axisLeft`, and a legend lists each country’s color from `d3.scaleOrdinal` with `d3.schemeCategory10`. The visualization uses an SVG rendering approach within a fixed-width container, labeling the y-axis in billions.