A bar chart displays the average calories of fast-food menu items for eight restaurant chains, using data from a local CSV file. The visualization aggregates the dataset with `d3.rollups` and `d3.mean` to compute per-restaurant averages. Built with React and D3 v7, the SVG chart uses `d3.scaleBand` for the categorical x-axis and `d3.scaleLinear` with `.nice()` for the y-axis, rendering steel-blue bars. Both axes are labeled, and restaurant names are rotated on the x-axis for readability.