This interactive scatter plot visualizes demographic and economic data for California counties, with dropdown menus allowing the user to select which columns map to the X and Y axes. The visualization uses D3 v5’s `scaleLinear`, `scalePoint`, and `axisBottom`/`axisLeft` to render the plot, and employs `transition().duration(2000).delay()` to animate circles as the selection changes. The X axis supports numeric fields like Income and Poverty, while the Y axis displays categorical county names. Data comes from the UCI Machine Learning Repository’s Auto MPG dataset.