Fork of Smiley Face Part IV
A React-driven D3 visualization renders a classic smiley face as a static SVG composition. The face consists of a yellow background circle with a black stroke, two eye circles, and a curved mouth path generated using D3's `arc` function with specified angles and radii. Fixed dimensions and coordinates position all elements relative to the canvas center, with the mouth arc defined by inner and outer radii and a half-turn angle range. The code imports `arc` from D3 v5 and uses React 16.9 to render the final SVG output.