This clustered bubble chart visualizes total and unit costs and total profit aggregated by region, with bubble size and opacity encoding the selected financial metric. Users can switch metrics via a dropdown menu, triggering a rebuild of the chart using D3 v7’s `d3.pack()` and `d3.hierarchy()` layout. Hovering reveals tooltips with exact values, while labels inside bubbles wrap using a custom text-wrapping function. The SVG renders with D3 selections, and data comes from a CSV of 100 sales records.