Which of the items below is NOT a diagrammatic document style suitable for documenting requirements?

Requirements may be documented using several diagrammatic styles where visual representation helps stakeholders understand scope, data, behaviour, or process flow. A use case model is diagrammatic because it shows actors, system boundaries, and use cases. A data model is diagrammatic because it represents data entities, attributes, and relationships. A business process model is also diagrammatic because it shows tasks, decisions, flows, hand-offs, and responsibilities. An epic, however, is normally a high-level Agile requirement or large user story, not a diagrammatic document style. It may be broken down into features or user stories, but the epic itself is textual rather than a modelling notation. Therefore, “Epic model” is the item that is not suitable as a diagrammatic document style for requirements.