Two dropdown menus let a viewer select which measurements of the Iris dataset appear on the x and y axes of an interactive scatter plot. The React app uses D3 v6 scales (`scaleLinear`, `extent`) to map values to an SVG canvas, while `AxisBottom` and `AxisLeft` render tick marks. Changing a menu updates the corresponding axis label and point positions via `useState`. The data is loaded from a CSV with `d3.csv`, and hovering over a circle reveals its exact value through a native SVG `<title>` tooltip.