A project is ready to start, and resources are allocated.

 When a critical resource becomes unavailable, it is essential for the project manager to first assess the situation and explore all possible resource allocation options based on the project’s priority. This involves identifying alternative resources, adjusting the project schedule if possible, and reallocating existing resources to maintain the project’s momentum and meet its objectives. The project manager should prioritize tasks and resources in a way that minimizes the impact on the project’s critical path and overall timeline. References: = The answer is verified by the discussion on resource allocation when a critical resource is unavailable, as found in the PMP topic discussions1. Further insights into adapting to schedule and resource delays, which align with the PMP’s guidelines on resource allocation, can be found in articles discussing the critical path and resource management234. Additionally, the Professional in Business Analysis Reference Materials provide guidance on working with stakeholders to define project requirements and shape project outcomes, which is relevant to resource management decisions56789.