Which of the following is a connection-oriented protocol ?

A protocol is connection-oriented when the sender and receiver first establish a session (commonly via a handshake) and maintain state for that session throughout the exchange, so that delivery can be tracked, acknowledged, and reordered if needed. A connectionless protocol instead sends each unit of data independently, with no session setup and no guarantee of delivery or order.

TCP (Transmission Control Protocol) begins every exchange with a three-way handshake — SYN, SYN-ACK, ACK — before any application data is sent. Once the connection is open, TCP numbers every byte, acknowledges receipt, retransmits lost segments, and closes the session explicitly at the end. This session-based, stateful behaviour is exactly what defines a connection-oriented protocol, so TCP fits the description in the stem.

Contrasting the other options confirms this:

• UDP sends each datagram independently with no handshake and no session state, so it is connectionless rather than connection-oriented.

• IP works at the network layer and forwards each packet on a best-effort basis without setting up or tracking any session between source and destination — also connectionless.

• HTTP is an application-layer protocol that defines request/response message formats between a client and server; it does not itself establish the transport session — it runs on top of a transport-layer connection (typically TCP).

Hence, among the given options, TCP is the connection-oriented protocol.