What is the relationship between work packages and project milestones?

The correct choice highlights that milestones are indeed defined by the completion of work packages. In project management, work packages represent discrete units of work that can be planned, executed, and measured. Each work package typically has specific deliverables and associated activities.

When a work package is completed, it often signifies an important point in the project lifecycle, marking progress and contributing to the overall project goals. These completion points help project managers assess whether the project is on schedule and achieving its objectives.

Therefore, milestones serve as reference points that indicate significant achievements or phases in the project timeline, most of which correlate directly to the completion of one or more work packages. By establishing these milestones, project managers can ensure they have checkpoints to monitor progress and adjust plans as necessary.