Explanation
The project manager should meet with the team member and search for the root cause of their behavior. This will help the project manager to understand why the team member is complaining about the agreement, and to address any issues or concerns that the team member may have. The project manager should also remind the team member of the importance of the agreement for the project success, and the need to respect the decisions made by the team. The other options are not effective or appropriate, as they may create more conflict, confusion, or resentment among the team members, or undermine the team's authority or commitment. References: PMBOK Guide, 7th edition, page 76, 78, 255.