In a Use Case diagram which of the following is represented by an Oval shape?

In a Use Case diagram, an Oval shape represents a function, which is also referred to as a use case. Each oval indicates a specific functionality or process that the system offers to its users, typically describing an interaction between the users (actors) and the system in terms of what they want to achieve. This visual representation helps to clarify the functionalities that the system provides and how they relate to the actors involved.

The use of ovals is a standardized format in Unified Modeling Language (UML), specifically for modeling use cases. Understanding this helps in clearly conveying user requirements and expectations, making it easier to identify the system's capabilities during development.

In contrast, other elements represented in the diagram have different shapes: associations are typically shown as lines connecting actors to use cases, system boundaries are often illustrated as rectangles that encompass the ovals, and actors are depicted with stick figure icons. This distinction in representation allows for a clear understanding of the overall system architecture and interactions.