Final answer:
The section of the Lean Canvas that shows progress by hitting essential milestones is Success Metrics.
Step-by-step explanation:
The section of the Lean Canvas that is meant to show progress by hitting particular milestones of development that are essential is A. Success metrics. This section focuses on defining specific metrics that indicate progress and success for the business. These metrics can include user adoption rates, revenue targets, customer satisfaction, or any other key performance indicators that are relevant to the business goals.