$[30$ seconds$]$ Select the false statement.

Because a connectionless service usually maps directly onto the underlying hardware, it is extremely efficient.

Connectionless service guarantees reliable, in$-$order delivery.

TCP$/$IP protocols define the unit of data transmission, called a datagram, and specify how to transmit datagrams on a particular network.

TCP$/$IP protocols include standards for many common applications including electronic mail, file transfer, and remote login$.$