A yellow smiley face rendered as a React component uses D3's `arc` generator to draw a thick mouth, with SVG circles for the eyes and background. The face is centered on a 960 by 500 SVG canvas, with the background circle's radius set to half the height minus half the stroke width. React 16.9 and D3 v5 are loaded via UMD scripts, and `ReactDOM.render` mounts the SVG tree to the DOM. The example demonstrates combining React's declarative components with D3's geometry utilities for static vector graphics.