This example shows a minimal force-directed graph with three nodes (Alice, Bob, Carol) and two links connecting them in a chain. Using d3.forceSimulation with forceManyBody, forceLink, and forceCenter, the graph runs a physical simulation to position the nodes. The SVG circles are added to a d3 selection bound to the node data, with a tick listener that updates their positions. The code demonstrates the basic setup for a force layout but does not yet implement the actual position updates in the tick handler.