Smiley Face Part I
A smiley face is drawn using React and D3 v7, rendered as SVG shapes. The face consists of a yellow background circle, two black eyes, and a curved mouth created with the `d3.arc()` generator. React components structure the code, with separate modules for the background, eyes, and mouth. The mouth’s arc geometry is defined by computed radius and angle values, while the entire group is centered using an SVG transform.