Which statement best describes how Transmission Control Protocol (TCP) provides reliable delivery?

### Why this is right TCP creates a session between the communicating devices. That session lets the receiver acknowledge received data and request missing data to be sent again, supporting reliable delivery. ### The concept Reliable transmission is useful when missing data or data arriving out of order would harm the application. TCP uses sequence information to help arrange data and session mechanisms to support acknowledgement and retransmission. These features require a larger header and state maintained by the end devices. User Datagram Protocol (UDP), by contrast, offers best-effort delivery and does not provide those reliability mechanisms itself. ### The other options - **B. It uses a smaller header and never tracks a session.**: This describes UDP's simpler approach, not TCP. - **C. It guarantees that packets arrive in their original order without using sequence information.**: TCP uses sequence information to help organize received data; ordering is not achieved by ignoring sequence information. - **D. It relies only on the destination port to confirm delivery.**: A port helps identify an application. It does not acknowledge packet delivery. ### Terms - **TCP**: Transmission Control Protocol. A transport protocol that supports reliable delivery using a session. - **UDP**: User Datagram Protocol. A transport protocol that provides best-effort delivery without TCP's reliability mechanisms. - **Header**: Control information attached to data, used to guide its delivery or processing. - **Destination port**: The transport-layer port used to direct incoming traffic to an application. - **Session**: A tracked communication relationship between devices. - **Retransmission**: Sending data again when it is missing or needs replacement. ### Remember TCP reliability comes from session-based acknowledgements and retransmission, not from port numbers.