When a late concern arises after prototype approval and development has started, the project manager should acknowledge the stakeholder, assess the request through the agreed change/priority mechanism, and preserve commitments needed to finish the current delivery. Placing the requirement into the next deliverable cycle (D) is typically the most practical action because it respects the already-approved baseline (or sprint/release commitment) while still addressing stakeholder needs via backlog/release planning. Being firm dismissively (A) damages relationships and fails stakeholder management. Documenting and "engaging more often" (B) is generally good practice, but the immediate next action is deciding how to handle the request within the current project's stage and commitments. Telling the stakeholder nothing can be done (C) undermines collaboration and ignores adaptive planning; even if it cannot be included now, it can be scheduled. Including it in a future cycle supports transparency, maintains delivery focus, and provides a structured path for evaluation (value, effort, impact) and prioritization-core PMP objectives around stakeholder engagement and integrated change control in an agile or hybrid setting.