This example demonstrates fundamental DOM manipulation with D3.js through an interactive smiley face whose eyebrows move. Users select a year (2011, 2012, or 2013) via radio buttons, and the chosen year appears in a text span. The visualization uses D3 v5 to bind data to SVG elements, with `d3.csv` imported for potential data loading, though the visible interaction relies on JavaScript event handlers (`onClick`) and direct DOM selection via `d3.select`. The rendering approach uses an SVG canvas sized at 960x500 pixels, with styles defined in an external CSS file.