The correct answer is D. defines an improvement project . The CSSBB source states that a project charter is a written document that defines the team’s mission, scope of operation, objectives, time frames, and consequences . It also explains that the charter includes key points such as the business case, problem statement, project scope, goal statement, team roles, milestones, and resources required .
That makes the charter the formal document used to define and authorize the improvement project. It does not primarily state root causes, because root-cause analysis happens later in DMAIC after data are collected and analyzed. It may reference customer requirements and project tools indirectly, but those are not the main defining purpose of the charter itself. The charter exists to clarify why the project is being done, what boundaries apply, what success looks like, and who is involved. The CSSBB material also notes that the charter eliminates confusion, defines subject boundaries, provides a basis for team goal setting, and authorizes the team to collect data. Therefore, the verified best answer is D. defines an improvement project .