Final answer:
The post-implementation review task is part of the operation phase, where the project's success is evaluated, and lessons learned are documented for future reference. Thus, the option D is the correct answer.
Step-by-step explanation:
The post-implementation review is a critical part of the Project Management Lifecycle, where stakeholders assess the project's success, identify best practices, and recognize areas needing improvement. This review typically happens during the operation phase of the project once the implementation phase has been completed, and the project deliverables are in use by the client or end-users. The post-implementation review is designed to assess whether project objectives were met, evaluate how effectively the project was managed, quantify the level of success in meeting the business case, and identify lessons learned to improve future projects. It's a continuous learning process integral for the growth and development of any organization's project management capabilities.