This interactive scatter plot visualizes the Iris dataset, letting users switch which flower measurements appear on the x- and y-axes via custom dropdown menus. Colored circles represent individual flowers, with colors mapping to species via a `d3.scaleOrdinal`. The reusable chart component uses `d3.scaleLinear` for axes, `selection.join` for enter/update/exit transitions, and animated transitions (`transition().duration(1000)`) to smoothly reposition and grow points when selections change.