Smiley Face Part 1
A smiley face is rendered as a yellow circle with two black eyes and an arched mouth, all drawn relative to a central point. The React app uses SVG elements for the face, while D3's `arc` generator creates the mouth path with specified inner and outer radii and start/end angles. The background circle, eyes, and mouth are positioned using computed offsets from the center, with the eye and mouth radii defined as constants. The code imports `arc` from `d3` and uses React's `ReactDOM.render` to mount the component.