Stakeholder engagement is a critical function of a project manager, especially when there is disagreement over decisions. The best course of action is to clarify the rationale behind the selection and use data-driven reasoning to influence the dissenting teams toward consensus.
According to the PMBOK Guide - Seventh Edition (Stakeholder and Communication Performance Domains), the project manager must ensure that stakeholders understand the process and are aligned with outcomes. Engaging in respectful discussions and influencing team members through facts and process transparency supports long-term collaboration and buy-in.
Option A escalates prematurely.
Option B is authoritarian and damages trust.
Option C neglects stakeholder engagement.
Reference:
PMBOK Guide - Seventh Edition, Stakeholder Engagement and Decision-Making Principles PMI Influence Without Authority Toolkit

When some team members are not engaged, it is critical to explore the root cause in a safe and collaborative manner. Conducting a team-building or issue-identification activity encourages open communication and uncovers barriers such as time zones, cultural differences, or unclear expectations.
According to the PMBOK Guide - Seventh Edition and Agile Practice Guide, engagement and psychological safety are key to high-performing teams. Identifying the cause first ensures that corrective actions are meaningful and not superficial.
Option B may be valid but assumes the problem is scheduling.
Option C is reactive and may be seen as confrontational.
Option D treats the issue as a risk without attempting resolution.
Reference:
PMBOK Guide - Seventh Edition, Team and Stakeholder Performance Domains Agile Practice Guide, Chapter 4 - Building High-Performance Teams

In a highly adaptive project environment, it is crucial to leverage the collective knowledge and experience of the team. Reviewing lessons learned from similar projects can provide valuable insights into potential challenges and effective strategies, which can help in creating practical plans with high levels of buy-in from team members. This approach aligns with the principles of adaptive project management, which emphasizes learning and continuous improvement.
The importance of reviewing lessons learned is supported by adaptive project management resources that highlight the value of iterative learning and team collaboration12. Additionally, the PMBOK guide underscores the significance of creating a collaborative project team environment, which includes learning from past projects to improve future outcomes3.