According to 'A Guide to the Business Analysis Body of Knowledge’1, the two most common data models are the entity-relationship diagram and the class model. These are techniques for representing the data elements and their relationships within a system or a domain23. An entity-relationship diagram shows the entities (or objects) and their attributes, and the relationships among them. A class model shows the classes (or types) of objects and their properties, and the associations and generalizations among them4. The other options are not data models, but rather techniques for modeling different aspects of the system or the project, such as the project network diagram (B), which shows the sequence and dependencies of the project activities, the data flow diagram ©, which shows the flow of data and information among the processes, or the WBS (D), which shows the breakdown of the project scope into smaller components. References: Business Analysis Expert Certification, CCBA® | IIBA®, Certification of Capability in Business Analysis™(CCBA®), Business Analysis Certification Competencies, CCBA® | IIBA®, A GUIDE TO THE BUSINESS ANALYSIS BODY OF KNOWLEDGE