To address prior tensions and focus the retrospective on constructive improvements, the project manager should set clear expectations for behavior and objectives. A well-structured agenda helps keep the discussion process-oriented and prevents blame. This approach aligns with Agile principles and effective facilitation practices. Option A prevents open communication and collaboration. Option B focuses only on leadership, not the whole team. Option D introduces unnecessary escalation and shifts focus from improvement to contract management. References: Agile Practice Guide, Chapter 5: Retrospectives and Continuous Improvement PMBOK Guide - Seventh Edition, Team Performance Domain (Feedback and Facilitation)