Answer:
The correct option is;
A. Three-way handshake
Step-by-step explanation:
For establishment of connection within Transmission Control Protocol, (T. C. P.), involves a three-way way handshake. Prior to attempting a server connection, the server to which connection is sought passively opens a port by listening at the port. Upon establishment of passive open, active open by the client can then be initiated by the client. A connection establishment requires a three-way handshake as follows;
1. The client sends a SYN to the server
2. The server responds by sending a SYN-ACK
3. The client further responds sending ACK back to the server.