Explanation
This answer is based on the principle of stakeholder engagement, which involves identifying and addressing the needs, expectations, and concerns of the project stakeholders, including the project team members. By having a meeting with the resource who wants to leave the project, the project manager can try to understand the reason behind this decision, and explore the possible options to retain the resource or mitigate the impact of the resource change. This will also help to maintain a good relationship with the resource and avoid any negative consequences for the project performance or morale. References: (Project Management Professional (PMP) Reference Materials source and documents) A Guide to the Project Management Body of Knowledge (PMBOK Guide) - Seventh Edition, Chapter
13: Engaging Stakeholders, Section 13.2: Planning Stakeholder Engagement, page 305.
The Standard for Project Management, Part 2: Value Delivery System, Section 2.1: Project Initiation, page 39.