Option 3: Use Case Model

A Use Case Model is an example of a Functional Model. It represents the functional aspects or behavior of a system by defining various use cases, actors, and their interactions. Use cases describe how the system functions from a user's perspective, focusing on what the system does to achieve specific goals or tasks.

The other options mentioned:

• Domain Object Model (Option 1): Represents the objects and their relationships within the problem domain.
• Physical Model (Option 2): Represents the physical aspects of a system, such as database tables, network architecture, and hardware components.
• Object Model (Option 4): Represents the objects, classes, and their relationships in a software system but doesn't specifically capture the functional behavior as the Use Case Model does.