This example shows a simple smiley face rendered as an SVG graphic using React and D3. The face consists of a yellow circle with a black stroke, two black eye circles, and a mouth drawn as an arc using the `d3.arc()` API with inner and outer radii. React manages the component structure and JSX markup, while D3 provides the arc path generator for the mouth shape. The code uses explicit pixel coordinates and constants for positioning, with the entire graphic centered at the midpoint of the 960-by-500 viewport.