A smiling face rendered in SVG with React and D3. The face features a silver circle, black eyes, and a mouth arc drawn with `d3.arc`. Nine rectangular teeth are placed around the mouth using a reusable `Tooth` component that rotates each tooth via a `transform` attribute. The code demonstrates how React components can encapsulate repeated SVG elements, replacing commented-out manual markup with a `Tooth` function that accepts a rotation prop. The example uses React 16.9 and D3 v5.