This visualization displays age distribution across U.S. states using a radial pie chart, where each state occupies a band segment and stacked segments represent age groups. The chart uses `d3.scaleBand` for angular positioning and `d3.scaleRadial` for radial extent, with `d3.stack` preparing the data from `data.csv`. A custom `d3-scale-radial.js` module provides the `scaleRadial` scale. SVG rendering includes axis circles, state labels, and a color-coded legend for the seven age brackets.