According to the PMI Risk Management Professional (PMI-RMP)Examination Content Outline1, one of the tasks in the domain of Risk Response is to call for a project team meeting to review risk strategies and make required adjustments, as needed, based on risk monitoring and reporting1. In this scenario, the risk manager should do this to address the situation of the availability of experts, which is a key risk for the project. The project team meeting will help the risk manager and the project team to evaluate the effectiveness of the current risk response plan, identify any new risks or changes in existing risks, and develop alternative risk strategies and actions to deal with the staffing issue. The project team meeting will also facilitate the communication and collaboration among the project team members and other stakeholders, and ensure that the project objectives and expectations are aligned. The risk manager should not implement a disciplined tracking method and report to stakeholders accordingly, because that is not a proactive risk response strategy, but rather a passive risk monitoring and reporting technique2. The risk manager should not escalate the staffing topic to the sponsor and request more budget for contingencies, because that is not a feasible or appropriate risk response strategy, as it does not address the root cause of the risk or provide a solution to the problem3. The risk manager should not revisit the project charter for scope adjustments and sign them off with the customer, because that is not a risk response strategy, but rather a scope management process that may have negative impacts on the project quality, cost, and schedule, and may violate the contractual agreement with the customer4. Reference: 1: PMI Risk Management Professional (PMI-RMP)Examination Content Outline, page 102: A Guide to the Project Management Body of Knowledge (PMBOKGuide) - Sixth Edition, page 4563: A Guide to the Project Management Body of Knowledge (PMBOKGuide) - Sixth Edition, page 4364: A Guide to the Project Management Body of Knowledge (PMBOKGuide) - Sixth Edition, page 133.

Explanation
sensitivity analysis is a technique that helps to determine which risks have the most potential impact on the project. It examines the extent to which the uncertainty of each project element affects the objective being examined when all other uncertain elements are held at their baseline values. Sensitivity analysis is often used to assess the risk exposure of the project schedule and cost, and to identify the critical risks that need to be managed. In this case, the risk manager needs to understand how the new risk resulting from the delay will affect the project deadline, which is the objective being examined. By performing sensitivity analysis, the risk manager can compare the relative importance and interaction of the new risk with other existing risks, and determine the worst-case scenarios for the project completion date. Sensitivity analysis can also help to prioritize risks for response planning and to develop contingency reserves. This is part of the Perform Quantitative Risk Analysis process in the PMBOK Guide2. References: 1: PMI Risk Management Professional (PMI-RMP) Examination Content Outline 2: A Guide to the Project Management Body of Knowledge (PMBOK Guide) - Sixth Edition

When describing the causes of a risk, it is critical for the risk manager to ensure that the causes represent actual conditions, as this will help in the accurate identification and assessment of the.
According to the PMBOKGuide, a risk is defined as "an uncertain event or condition that, if it occurs, has a positive or negative effect on one or more project objectives" (page 720). A risk can be described by its causes, effects, and probability of occurrence. The causes are the factors or circumstances that give rise to the risk, and they should represent the actual conditions that exist or may exist in the project environment. The causes should not be based on assumptions, opinions, or speculations, but on facts, evidence, or data. Therefore, option C is the correct answer.
Option A is incorrect because not every cause has a degree of uncertainty. Some causes may be certain or deterministic, such as contractual obligations, regulatory requirements, or physical laws. Uncertainty is a characteristic of the risk itself, not the cause.
Option B is incorrect because not every cause has a well-defined owner. The owner is the person or entity who is assigned the responsibility and authority to manage the risk, not the cause. The owner should be identified after the risk is analyzed and prioritized, not before.
Option D is incorrect because the causes do not need to be validated by the risk owner. The risk owner is the person or entity who is accountable for the risk response, not the risk identification. The causes should be validated by the risk manager or the risk identification team, who are responsible for collecting and documenting the risk information.

The project manager should monitor and control secondary and residual risks in the risk register. This will ensure that any new risks identified during the implementation of the risk response plan are captured and managed effectively. Monitoring and controlling risks is a continuous process that helps in identifying, analyzing, and planning for new risks as well as updating the risk register as needed.
According to the PMI Risk Management Professional (PMI-RMP)®Examination Content Outline, one of the tasks under the domain of Risk Response Planning is to "identify and assess the effectiveness of alternative strategies to reduce threats or enhance opportunities, such as mitigation, transference, avoidance, and acceptance" 1. This implies that the project manager should also consider the potential secondary or residual risks that may arise from implementing the chosen risk response strategy. Secondary risks are new risks that are created as a direct result of implementing a risk response, while residual risks are those that remain after therisk response has been executed 2. Both types of risks should be identified and assessed for their impact and probability, and added to the risk register for further monitoring and control. Therefore, the correct answer is A.
References: 1: PMI Risk Management Professional (PMI-RMP)® Examination Content Outline, page 91 2:
A Guide to the Project Management Body of Knowledge (PMBOK® Guide) - Sixth Edition, page 4362