A smiling face rendered with SVG primitives inside a React component, using circles for the face and eyes and a D3 arc path for the mouth. The code sets D3’s `arc()` generator with explicit inner/outer radii and start/end angles to create the curved mouth path, then draws the face, eyes, and mouth on a 960 by 500 canvas. React manages the SVG output, while D3 v5 computes the path data, and CSS hides page margins for a full-viewport display.