Which of the following best describe the value of using a kanban board?

A kanban board allows your team to show others in the company what work they need subcontractors for.
A kanban board allows the entire team to see and optimize the flow of work during the current sprint.
A kanban board allows the clients to see exactly how much time is being spent on each task.
Kanban boards are popular with the development team, however, are not as useful to the strategist or clients themselves.