Let's make a face with D3.js!
A yellow smiley face rendered in SVG demonstrates fundamental D3.js DOM manipulation. The face uses D3 v5's `select` and `arc` to append a circle, eyes, and a mouth, with the mouth created via the `arc()` generator. Eyebrows, drawn as rectangles, animate upward and downward through chained `transition().duration()` calls, while the mouth also shifts position over two seconds. All elements are positioned within a centered `<g>` group, showing basic SVG construction and data-driven updates.