This example demonstrates how to begin using D3 version 7 by loading a CSV file of country populations and preparing to render them as SVG rectangles. The code uses `d3.csv` to fetch data, `d3.scaleLinear` to map population values to pixel widths, and `d3.max` to determine the scale domain. Population figures are multiplied by 1000 before rendering. The visualization is incomplete—the bar chart is not fully drawn—but it serves as a minimal starting point for learning D3's data-binding workflow with `select` and `selectAll`.