According to the PMBOK® Guide, specifically the Stakeholder Engagement and Communications Management knowledge areas, the arrival of a new key stakeholder is a significant change that requires immediate management action.

Why Choice C is correct:

Assess and Align: The project manager must first engage with the new stakeholder to understand their specific information needs, expectations, and influence on the project. This is a prerequisite to any other action.

Clarify Procedures: By engaging directly, the PM can explain the existing Communications Management Plan and the established reporting cadence. This prevents team disruption (team members being distracted by ad-hoc requests) while ensuring the stakeholder feels supported.

Relationship Building: Building rapport with a " key " stakeholder early is essential for long-term project success and conflict prevention.

Analysis of other options:

A (Extend an iteration review invite): While this is a good secondary step for transparency (especially in Agile), it doesn ' t address the immediate issue of the stakeholder ' s " out of sequence " report requests. The PM first needs to understand why they need those reports before just inviting them to a meeting.

B (Perform qualitative risk analysis): While the change in stakeholders is a risk, the PMBOK® Guide emphasizes that personal engagement and communication management are the primary tools for stakeholder issues. Risk analysis is a backend process; engagement is the active resolution.

D (Allow team members to share reports): This is incorrect. Allowing " out of sequence " reporting bypasses the Communications Management Plan and the Change Control processes. It leads to " noise, " potential misinformation, and wastes the team ' s productive time. The PM should act as a buffer.

Key Concept: When a new stakeholder enters the project, the Project Manager must perform the Identify Stakeholders and Plan Stakeholder Engagement processes. Choice C is the " first " logical step in these processes—initiating a dialogue to align the stakeholder ' s needs with the project ' s governance framework.