Which of the following is used to monitor progress?

The burn-down chart is a visual tool used in agile to monitor progress by tracking the remaining work against time. It provides teams and stakeholders with a clear, real-time view of project status and forecast completion, allowing for early identification of potential delays or bottlenecks.

The delegation matrix (A) defines authority, swarming (B) is a team collaboration technique, and t-shirt sizing (C) is an estimation method, none of which directly monitor progress.