A bar chart displays twenty data values as vertically oriented rectangles, each labeled with its numeric value. Clicking the prompt text triggers a one-time update with a new dataset. The visualization uses D3 v4.5.0 to construct an SVG scene with `d3.scaleBand` for x-axis positioning and `d3.scaleLinear` for bar heights. The update applies a `transition` with a controlled `duration` of 1000 milliseconds, smoothly animating the rectangles' y-coordinates, heights, and fill colors. Text labels update instantly without transition.