This example builds a smiling face using D3.js v5 and SVG primitives. A yellow circle forms the head, with two black circles positioned as eyes and a mouth drawn as a path generated by D3’s `arc` function. The face is centered by translating a group element to the middle of the SVG canvas, with eye spacing and offsets set as constants. The code demonstrates basic D3 selections, attribute assignment, and arc path generation for simple geometric compositions.