This interactive scatter plot displays demographic and economic data for California counties from the UCI Machine Learning Repository’s Auto MPG dataset, with a dropdown menu letting users switch the x-axis variable. Built with D3 v5, it uses `scaleLinear`, `scalePoint`, and `axisBottom` for axes, and animates circles via `transition().duration()` and `delay()` when the selection changes. The SVG rendering includes a title and axis labels, with data loaded asynchronously using `csv()`.