Explanation
According to the PMBOK Guide, 7th edition, one of the project manager's responsibilities is to apply relevant knowledge and experience from previous projects to the current project1. This can help the project manager to identify best practices, avoid pitfalls, and improve the project performance2. Therefore, the project manager should review the lessons learned from the previous project that developed the existing product, as they may provide valuable insights and recommendations for enhancing the product. This can also help the project manager to align the project objectives with the organizational strategy and customer needs3. Ensuring the stakeholder engagement plan is accurate and properly documented (option A) is an important task, but it is not the first thing the project manager should do when initiating a project. Creating a lessons learned document for the initiation phase (option B) is a good practice, but it is not the answer to the question, as it is something the project manager should do at the end of the initiation phase, not at the beginning. Identifying the risk of implementing the new solution and evaluating the impact on the project (option C) is also a vital task, but it is not the answer to the question, as it is something the project manager should do during the planning phase, not the initiation phase. References: 1: PMBOK Guide, 7th edition, page 25 2: PMBOK Guide, 7th edition, page
26 3: PMBOK Guide, 7th edition, page 27