This bar chart shows the average radius mean of cell nuclei grouped by diagnosis (M for malignant, B for benign). The chart uses a vertical bar layout with a color-encoded categorical scale and displays the numeric value above each bar. Built with D3 v7, it loads CSV data, aggregates values using `d3.rollups` and `d3.mean`, and renders an SVG with axes, a grid, and hover opacity effects. The data source is a remote GitHub-hosted CSV file.