Which protocol is used to control the way data packets are sent over the network?

The Transmission Control Protocol/Internet Protocol (TCP/IP) suite is fundamental for the functioning of the internet and many networks. TCP, in particular, plays a crucial role in how data packets are transmitted. It establishes a reliable connection-oriented communication channel between devices and ensures that data packets are sent, received, and reassembled in the correct order. This involves error checking, flow control, and ensuring that packets are retransmitted if they are lost during transmission.

While the other protocols mentioned, such as HTTP (used for transferring web pages), FTP (used for file transfers), and IMAP (used for retrieving email), serve specific purposes in data communication, they do not primarily manage the way packets are sent over the network. Instead, they operate at higher levels of the protocol stack, using TCP/IP to handle the underlying transmission of data packets. Therefore, TCP/IP is the correct choice for controlling data packet transmission over the network.