Solution

The Transport layer in both the OSI and TCP/IP models is responsible for end-to-end communication, ensuring data integrity, and providing error correction and flow control. In the OSI model, this layer (Layer 4) establishes, maintains, and terminates connections, handling segmentation, acknowledgment, and retransmission of lost data. The TCP protocol (in the TCP/IP model) works at this layer to provide reliable, connection-oriented services, making it essential for consistent data delivery in network communication. Why Other Options are Incorrect: A) Application: The Application layer (Layer 7 in OSI) provides services to the end-user, not responsible for transport-related tasks. B) Presentation: The Presentation layer (Layer 6 in OSI) deals with data format translation and encryption but not transport. C) Session: The Session layer (Layer 5 in OSI) manages sessions between applications, not data transport. E) Network: The Network layer (Layer 3 in OSI) is responsible for routing and logical addressing (IP addresses), but not the end-to-end data transmission duties handled by the Transport layer.