A Work Breakdown Structure has been completed. The project team is now collecting estimated activity duration times so that a schedule can be created. To estimate each activity several people who are responsible for completing the activities in the project are asked for time estimates. But as the team collects these estimated times they find considerable variance from one person's estimate to another's. Some have been more ambitious than others in determining what needs to be done. Which additional document would help clarify the situation?

Risk Breakdown Structure

Schedule

Scope Statement

Business Case