This visualization plots depression rates against happiness scores for different countries, with each circle representing a country and its position determined by those two metrics. A dropdown menu allows viewers to select a specific year, triggering a smooth transition of the data points. The chart uses D3 v6’s scales (`d3.scaleLinear`), axes (`d3.axisBottom`, `d3.axisLeft`), and SVG circles, with an animated `transition` to update positions when the year changes. Data is loaded from a CSV file via `d3.csv`.