The best approach in this situation is for the project manager to engage directly with the experienced team member to address the behavior. This should be done in a supportive manner, aiming to understand the reasons behind the team member's actions and to find a constructive way forward. This aligns with conflict resolution strategies that emphasize problem-solving and collaboration, which are considered effective in project management and business analysis contexts. By addressing the issue privately, the project manager can prevent further team disruption and work towards a resolution that maintains team cohesion and productivity.
: The answer is verified with the principles of conflict resolution as outlined in the PMBOKGuide and the Professional in Business Analysis (PMI-PBA) reference materials, which suggest that direct and supportive communication is key to resolving such conflicts123.

To resolve the conflict, the project manager should communicate with the former supervisor now serving as a resource to clarify the roles and responsibilities within the new project. This approach aligns with conflict resolution strategies that emphasize clear communication and role definition to prevent misunderstandings and ensure that each team member understands their place and function in the project. It is essential for maintaining harmony and focus within the team, especially during transitions12.
References:
PMBOK Guide, which provides guidelines on team roles and conflict management1.
The PMI Guide to Business Analysis, which includes standards for stakeholder engagement and communication2.

The closing phase of project management is the final phase of the project lifecycle. This is the stage where all deliverables are finalized and formally transferred, and all documentation is signed off, approved, and archived1. The most important step of the project closing phase is getting formal sign-off and acceptance of the customer2. Because projects are initiated based on a business need and customer request. Therefore, if the customer does not accept the final outputs and product, a project cannot be closed2. References: 7 Steps to Nail the Project Management Closure Process, Project Closing Phase: Do You Know the 8 Steps for Closing a Project?

The project manager should address the issue directly and promptly with the team member involved. One-on- one dialogue helps reset behavioral expectations and maintains professional conduct when dealing with customers. It also shows leadership and reinforces team norms.
Option A may be necessary later but may embarrass the individual if done publicly.
Option C may show empathy but avoids addressing the issue.
Option D is too broad and doesn't directly resolve the immediate behavior.
References:
PMBOK Guide - Seventh Edition, Team Performance and Stakeholder Engagement Domains PMI Code of Ethics and Professional Conduct (Responsibility and Respect)