In a Use Case diagram which of the following is represented by a Line?

In a Use Case diagram, a line represents an association. An association is the relationship between an actor and a use case, indicating that the actor is involved in or interacts with that particular use case. This visual connection helps to illustrate how different elements in the system interact with one another and is essential for understanding the flow of actions and responsibilities in the system being modeled.

The presence of the line allows viewers of the diagram to easily discern which actors are linked to which use cases, reinforcing the interactions that define the scope of the business processes being analyzed. By showing these relationships clearly, the diagram serves as a crucial tool for requirements gathering, system design, and communication among stakeholders.