This example visualizes the classic Iris dataset as a scatter plot, with dropdown menus that allow the user to select which of the four flower measurements appears on the x-axis and y-axis. Clicking the confirmation button updates the chart, recalculating the linear scales and redrawing the circles. The SVG rendering is built with React and D3 v5, using `scaleLinear`, `extent`, `axisLeft`, and `axisBottom` for axes. Points are colored by species (red, green, blue) and the chart includes labeled axes and gridlines.