Five gray circles demonstrate different D3 event bindings: the first changes color on click, the second on mouseover, the third on mouseout, and the fifth on contextmenu. A fourth circle, given an id, moves via WASD key presses using d3.transition() with a duration of 1000ms. The circles render as SVG, sized 1600 by 800, with random colors from d3.interpolateRainbow. Event handlers use d3.select and event.currentTarget to update fill attributes.