According to the PMBOK® Guide (6th and 7th Editions) and the PMI Talent Triangle, the root cause of low commitment and underperformance often traces back to the Planning Process Group and Resource Management.

Why Choice B is correct: Commitment is directly linked to Stakeholder Engagement and Resource Management. When team members are involved in the planning process (using a bottom-up approach), they develop a sense of ownership and accountability for the tasks they helped define. Open and transparent planning ensures that team members understand the " why " behind the project and their specific role in its success. By engaging them early, the Project Manager can identify potential resource conflicts (such as members being over-allocated to other projects, as shown in your image) and secure their buy-in, which prevents underperformance caused by a lack of motivation or clarity.

Analysis of other options:

A (Coupled inexperienced team members...): This is a technique for Knowledge Transfer or mentoring. While helpful for skill gaps, it does not solve the fundamental issue of commitment or being stretched across multiple projects.

C (Held regular meetings more often): This is a Monitoring and Controlling activity. While it might catch underperformance after it happens, the question asks what should have been done to avoid the situation initially. Increasing meetings can sometimes decrease morale if the underlying commitment isn ' t there.

D (Diversified the project team): Diversity is excellent for innovation and problem-solving, but it is not a direct solution for a lack of commitment or poor individual performance.

In the context of the provided image, where a team member states they are " working on another project as well, " this highlights a failure in Resource Acquisition and Negotiation. Transparent planning would have revealed these competing priorities during the planning phase, allowing the Project Manager to negotiate for dedicated time or adjust the schedule accordingly.