According to the PMBOK Guide, one of the tools and techniques for the plan risk management process is ground rules. Ground rules are the rules of conduct or behavior that are established by the project team and other stakeholders to ensure a productive and respectful environment for risk management activities. Ground rules can cover various aspects of risk management, such as roles and responsibilities, communication protocols, decision-making processes, meeting agendas, and conflict resolution methods1. By referring to the team’s ground rules on how to resolve conflicts, the risk manager can handle the situation where two key external stakeholders are overemphasizing the impact of a few project risks. This can help the risk manager to maintain a constructive and collaborative atmosphere in the risk reassessment workshop, as well as to ensure that the risk analysis and prioritization are based on objective and consistent criteria.

Some of the other options are not relevant or appropriate for the question scenario:

Requesting for a skilled facilitator to help resolve conflicts that have arisen is not a feasible or effective option, as it would interrupt the flow of the risk reassessment workshop and delay the risk management process. The risk manager should be able to facilitate the workshop and handle conflicts by themselves, using the tools and techniques that they have planned and agreed upon with the project team and stakeholders.

Running a sensitivity analysis to check which risks have the most impact is a technique for the perform quantitative risk analysis process, which is not applicable in the context of a risk reassessment workshop. A sensitivity analysis is a quantitative method that examines the effect of varying one risk parameter at a time on the project objectives, such as cost or schedule. It is not a tool for resolving conflicts or validating the impact of risks, as it does not consider the interrelationships and dependencies among risks or the probability of risk occurrence1.

Using the assumption analysis technique to validate the assumptions is a technique for the identify risks process, which is not suitable for the situation where conflicts have already arisen in the risk reassessment workshop. An assumption analysis is a technique that explores the validity of the assumptions that are made during the project planning and risk management processes. It is not a tool for resolving conflicts or verifying the impact of risks, as it does not address the root causes or the consequences of the disagreements among the stakeholders1.

PMBOK Guide, 6th edition, pages 407-408, 431-432, 437-438, 441-4421; PMI-RMP Exam Content Outline, 2015, pages 7-8.