You are the project manager for a software project using a hybrid lifecycle. During planning you identified a risk that a technical resource for a critical-path activity might be unavailable. One week before that activity starts, the assigned engineer has a personal emergency and takes leave. What should you do next?

The correct action is to consult the risk register and implement the planned risk response. Proactive risk management involves identifying potential risks and developing strategies to address them before they occur. Since this risk was identified during planning, a response should already be documented in the risk register. Implementing this pre-defined response is the most efficient and effective way to manage the situation. Revising the project management plan and rescheduling the task is a reactive measure that might be necessary if no adequate risk response was planned, but it's not the first step when a response should exist. Reviewing business requirements to remove the task is an extreme measure that could impact project scope and objectives. Updating lessons learned and the risk log are important administrative steps after the risk has been addressed, not the immediate action to resolve the current issue.