This example presents an interactive scatter plot of automotive data from the auto-mpg dataset, where users select which columns to display on the x- and y-axes via dropdown menus. Two menus are rendered using the custom `dropdownMenu` module, and the scatter plot is built with D3 v5, using `scaleLinear`, `axisBottom`, and `axisLeft` for scales and axes. Each data point is an SVG circle that animates into place with a 2-second transition, using `transition.attrTween`-like behavior through `transition().duration()`, with opacity set via CSS.