Which three layers of the OSI model correspond to the application layer of the TCP/IP model?

The application layer of the TCP/IP model encompasses several functions that are defined across three layers of the OSI model: the session layer, the presentation layer, and the application layer itself.

The application layer in TCP/IP is responsible for providing network services to end-user applications, managing the data communication between devices, and ensuring that the transmitted data is understandable. Each of these functions corresponds to different OSI layers.

The session layer manages sessions and controls the dialogues between computers, maintaining connections and managing their status. The presentation layer is responsible for data translation, formatting, and encryption or compression, ensuring that data is presented in a usable format for the application layer. The application layer of the OSI model deals directly with the application itself, handling protocols and data exchange that the user interacts with.

Thus, the correct answer corresponds to the presentation layer, as it plays a crucial role in formatting data for applications, making it integral to the overall process of the application layer within the TCP/IP model. The inclusion of the session and application layers from OSI highlights the broader scope of services that the TCP/IP application layer encapsulates.