This example builds a yellow smiley face from modular React components, combining circles and a D3 arc path inside an SVG. The face is centered via a `FaceContainer` that translates a group, while `BackgroundCircle` draws the yellow head with a black stroke, `Eyes` places two black circles, and `Mouth` uses d3’s `arc()` generator with start and end angles to form a smile. The code relies on React 16.9 and D3 v6, rendering declaratively with JSX and static numeric constants rather than data.