Final answer:
Uncontrollable variables refer to changes or growth in project deliverables that cannot be controlled by the project team.
Step-by-step explanation:
The changes or growth in deliverables that cannot be controlled in a project are referred to as uncontrollable variables. These variables are external factors that can impact the project's progress and outcomes, but are beyond the project team's control.
For example, economic changes, government regulations, market trends, and natural disasters are all uncontrollable variables that can affect project deliverables. Despite careful planning and execution, these factors can introduce unexpected challenges and require project teams to adapt their strategies and approaches.