This example shows how an interactive scatterplot lets users explore relationships between variables in the classic 1970s automobile fuel-efficiency dataset. Through dropdown menus, users select which numeric columns (such as miles per gallon, horsepower, or weight) map to the X and Y axes, and optionally group points by model year or origin via a categorical legend. A slider and numeric input control circle size and opacity. Built with React and D3 v5, the visualization uses `scaleLinear`, `axisBottom`, `axisLeft`, and `scaleOrdinal` with animated transitions on SVG circles, plus a custom tooltip that appears on mouseover, displaying the values for the currently selected axes.