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. References: PMBOK Guide - Seventh Edition, Team and Stakeholder Performance Domains Agile Practice Guide, Chapter 4 - Building High-Performance Teams