This interactive scatter plot lets users explore healthcare cost data by selecting X, Y, and color attributes from dropdown menus. The D3 v5 visualization uses a time-based X-axis for the year column and linear scaling for other metrics, with color encoding via `scaleOrdinal` and `schemeCategory10`. A `colorLegend` component displays the categorical scale, while the `scatterPlot` module animates circles with `transition().duration(2000)` as users change selections, all rendered as SVG elements.