What task is the project manager performing when they respond to a client request for a feature by stating the need to hire more people?

The project manager's response to the client request for a feature suggests that the current team may not have the capacity to deliver the requested changes without additional resources. By stating the need to hire more people, the project manager is directly addressing a resource allocation issue, which typically links to the project's budget. This implies that hiring additional personnel would impact the financial aspects of the project, necessitating an update to the project budget to accommodate the costs associated with those new hires.

Understanding the implications of resource management on the budget is crucial for ensuring that project objectives are met within financial constraints. The need for careful monitoring of the budget when considering additional resources underlines why this is the most relevant task at hand.

In the context of the other options, proactive communication involves engaging with stakeholders; validating deliverables does not directly relate to hiring decisions; and updating the project timeline, while important, would typically follow after confirming budget and resource adjustments. Thus, the focus on modifying the budget is the sound course of action when additional resources are required to meet client demands.