TCP／IP(71)layer protocols provide services to the application(72)running on a co

TCP/IP(71)layer protocols provide services to the application(72)running on a computer. The application layer does not define the application itself, but rather it defines(73)that applications need--like the ability to transfer a file in the case of HTTP. In short, the application layer provides an(74)between software running on a computer and the network itself. The TCP/IP application layer includes a relatively large number of protocols, with HTTP being only one of those. The TCP/IP(75)layer consists of two main protocol options--the Transmission Control Protocol(TCP) and the User Datagram Protocol(UDP).

A．application

B．transport

C．link

D．network

A