Which term describes a framework in which events drive control of an app?

• A. Model-View-Controller
• B. Architectural Pattern
• C. Observer Pattern
• D. Event Model

Answer: (D)

In an event-driven approach, the flow of the program is determined by events—such as user actions or messages—rather than a fixed sequence of steps. This is captured by the Event Model, where a central event loop dispatches handlers in response to each event, so control moves only when something happens. This setup is common in graphical interfaces and web apps, where clicks, keystrokes, or incoming data trigger specific functions.

Other terms describe different ideas: Model-View-Controller focuses on separating concerns among data, UI, and input handling rather than naming the overall event-driven framework; the Observer Pattern deals with notifying interested parties about changes, not the broader mechanism for driving control flow; and Architectural Pattern is a broad descriptor that doesn’t specify how control is driven by events.