This example shows a stacked bar chart that visualizes soil condition data across different plant groups. It uses a dropdown selector (initialized but not populated with options) and renders the chart as SVG using D3.js v4. The code loads CSV data from a remote GitHub source, applies a sequential color scheme from `d3-scale-chromatic`, and constructs the stacked layout using `d3.stack()`. Bars are drawn with `d3.scaleBand` for the X-axis and a linear scale for the Y-axis, with axes added via `d3.axisBottom` and `d3.axisLeft`.