This example demonstrates a minimal D3.js setup within a React framework, rendering a single red SVG rectangle as the main visual output. The code uses D3’s `select` function to grab the SVG element and apply a red background style, while also appending a paragraph with the text “hey” to the page body. The SVG is 400 by 200 pixels, generated via HTML, and all D3 operations are executed through the `bundle.js` script. The visualization serves as a basic introduction to integrating D3 with React and SVG rendering.