Two dropdown menus let viewers select which columns of a dataset appear on the x- and y-axes of a scatter plot. The visualization uses D3 v5’s `scaleLinear`, `axisBottom`, `axisLeft`, and `extent` functions to map numeric values, while a custom `dropdownMenu` module builds the `<select>` elements. Circles animate into position with `transition().duration(2000)` and a staggered delay, and the data comes from a CSV file containing movie attributes like budget, gross, and IMDb score.