Comprehensive and Detailed
When a new compliance policy is introduced, the project manager must evaluate how it may impact the project. Addressing blockers (obstacles that arise due to the new policy) ensures the project can continue progressing while maintaining compliance. This is a proactive approach to risk and issue management.
* A ignores a potential external constraint (noncompliance risk).
* B is vague and does not focus on risk response.
* D may be useful but is not immediately action-oriented.
* C aligns with risk management best practices.
Reference:
* PMBOK Guide - Seventh Edition, Risk Management Performance Domain
* PMI Governance and Compliance Best Practices

The best practice in project management, as per the PMP objectives, is to mitigate risks associated with resource availability by facilitating cross-functional knowledge transfer. This ensures that multiple team members are skilled in various components of the project, which allows for continuity of work in the event of an absence. The PMBOK Guide emphasizes the importance of knowledge transfer to enhance the team's ability to manage project risks and maintain productivity1.
: = Project Management Professional (PMP) Reference Materials, particularly the sections on risk management strategies1, and the Professional in Business Analysis (PMI-PBA) Reference Materials, which discuss the knowledge areas relevant to risk mitigation and resource management23.

Ask the sponsor for an experienced team member in the company to help the project team.
Explanation:
According to the PMBOK Guide, an issue log is a project document that records problems in a project and how they are resolved. A resource management plan is a component of the project management plan that describes how resources will be estimated, acquired, developed, managed, and controlled. When a team member leaves the company, the project manager should update the issue log with the details of the problem and the impact on the project. Then, the project manager should refer to the resource management plan to find out how to deal with the resource gap, such as reassigning tasks, hiring a new team member, or requesting additional resources from the sponsor or other stakeholders.
PMBOK Guide, 6th edition, pages 89-90, 318-319, 374-375
Agile Practice Guide, pages 32-33, 77-78

The project manager should first revisit the project charter and assess if the project goals and objectives can be met with other alternatives. This could include re-evaluating the project requirements, researching other suppliers and/or re-designing the project in order to reduce the cost. If all other alternatives are exhausted, then the project manager should seek approval from the project sponsor or the CEO to proceed with the purchase order.

In the context of Project Management Professional (PMP) practices, when a key function is anticipated to take longer to complete, the project manager should engage with the project team to review options and possible solutions. This approach aligns with the principles of iterative planning and agile methodologies, which emphasize collaboration, team engagement, and adaptive planning to address changes and challenges that arise during project execution. It is essential to work with the team to understand the issue's impact on the project's schedule and scope and to explore all possible avenues to mitigate delays while maintaining quality and meeting project objectives.
The answer is verified by the principles found in the PMI's guide to the Project Management Body of Knowledge (PMBOK Guide) and the Disciplined Agile (DA) toolkit, which advocate for a collaborative approach to problem-solving within the team and adapting plans as necessary based on the team's velocity and iteration goals12.