This is because use case diagrams are graphical models that show the actors, use cases, and relationships involved in a system or a solution. Use case diagrams are part of the business requirements document, as they help to analyze and refine the functional requirements and design of the solution. The models were not included as a mistake (A), as use case diagrams are nottechnical, but business-oriented. The models are not part of the technical documents (B), as they do not describe the implementation details of the solution, but the business needs and objectives. The models did change the value compared to text based requirements (D), as they provide a visual and concise way to communicate the requirements and design. References: CCBA Practice Test, CCBA Mock Test