This example renders a smiling face as an SVG graphic using React and D3. It shows a yellow circle with a thick black stroke, two ellipses for eyes, and a mouth created with a D3 arc generator. The face is centered on a 960 by 500 pixel canvas, with the mouth drawn using the `d3.arc()` function’s `innerRadius`, `outerRadius`, and angle settings. React components define the SVG elements, while D3 v5 handles the arc path generation for the mouth shape.