A simple SVG face rendered with D3.js, composed of a yellow circle for the head, two black circles for eyes, and an arc-shaped mouth. The face is centered within an 800 by 800 SVG canvas using D3 selections and attribute setters. The mouth is created with the d3.arc() function, specifying inner and outer radii and start and end angles. This example demonstrates importing D3 modules like `select` and `arc` from the library loaded via CDN.