This example shows a yellow smiley face composed of a large background circle, two eyes, and a curved mouth, all rendered as SVG elements. React manages the component structure, while D3’s `arc` function generates the mouth path using specified inner and outer radii and start/end angles. The `BackgroundCircle` component is a reusable React piece, and the entire graphic is centered via a `<g>` transform. The code uses React 16.9, D3 v5, and the `arc` API, with no external data source.