This example shows a simple smiley face rendered as SVG shapes, with a yellow circle for the head, two black eyes, and an arc for the mouth. It combines React for component-based UI structure with d3.arc for generating the mouth path. The code uses ReactDOM to mount the SVG into the page, and d3.js version 7 provides the arc generator with specified inner and outer radii. The face is centered on a 960×500 viewport using SVG groups and transforms.