The OSI seven-layer model includes Application, Presentation, and Session layers among its top three.

• A. True
• B. False
• C. Only Application layer exists
• D. It has more than seven layers

Answer: (A)

The OSI model defines seven layers, and the upper three are the Application, Presentation, and Session layers. These sit at the top of the stack and directly support how applications interact with the network: the Application layer provides interfaces for software to use network services, the Presentation layer handles data formatting, encryption, and compression, and the Session layer manages and maintains conversations between end systems. That arrangement is why the statement is true. The other options don’t fit: there are exactly seven layers, not more; it’s not just the Application layer alone; and there isn’t any extra layer beyond seven.