What tool will a project manager most likely use to update the project sponsor and stakeholders about project progress?

A project manager will most likely use milestones to update the project sponsor and stakeholders about project progress because milestones represent significant points or achievements in a project's timeline. They provide clear indicators of progress and can effectively communicate whether the project is on schedule, ahead, or lagging behind.

Milestones help in summarizing the progress made at various stages and can identify key deliverables that have been completed. This way, stakeholders can quickly assess how much has been accomplished relative to the planned schedule. They are particularly useful in reporting not just what has been completed, but also shaping the narrative around the project's trajectory and next steps.

While tools such as Gantt charts and Kanban boards serve important roles in project management—like providing a visual overview of tasks and progress—milestones directly highlight significant achievements and are a more focused way to report progress to stakeholders. The project charter, on the other hand, outlines the project's scope and objectives rather than its progress. Thus, milestones are the most effective tool for this specific purpose.