This example shows a smiling face built with React and rendered as SVG, combining D3’s arc generator for the mouth with React elements for the eyes and head. The face is centered within a 300×250 viewport, featuring a yellow circle with a black stroke, two small dark eyes, and a D3-generated mouth arc. The code uses `d3.arc()` to create the mouth path, while React’s `ReactDOM.render` mounts the component into the DOM. A dashed CSS oval is also defined but not used in the final output.