A simple SVG smiley face rendered in React, using D3’s `arc()` to generate a curved mouth. The face consists of a yellow circle with a blue stroke, two black eye circles, and a half-ring mouth, all positioned within an SVG group. Built with React 17 and D3 v6, the visualization is purely static and displays centered on a 900×450 canvas. The code uses `ReactDOM.render` to mount the component and D3’s `arc` API to define the mouth’s inner and outer radii and its angular span.