Smiley Face
A yellow smiley face rendered with React and D3.js uses SVG circles for the head and eyes, and a D3 arc path for the mouth. The `d3.arc()` API defines the mouth’s inner and outer radii, with start and end angles creating a curved smile. Stroke width and offsets position the facial features relative to the canvas center. The static composition relies on hard-coded dimensions and D3’s arc generator, with no interaction or animation.