Correct, option 'A' is the correct answer.
The Transmission Control Protocol/Internet Protocol (TCP/IP) is a set of communication protocols used to interconnect network devices on the internet. It is the standard for communication on the internet and it is a hierarchical protocol.
The Application layer of the TCP/IP protocol stack corresponds to the OSI model's Application, Presentation, and Session layers. The Application layer provides the interface between the application programs running on the host and the transport layer, it provides the necessary services to support the applications running on the host, such as email, file transfer, and web browsing.
The OSI model's Application layer provides the interface between the application and the network, it provides the necessary services to support the applications running on the host, such as email, file transfer, and web browsing. The Presentation layer is responsible for the syntax and semantics of the information exchanged between systems, it deals with the data representation, conversion, encryption, and compression. The Session layer establishes, maintains and synchronizes the interactions between systems.
In summary, the Application layer of the TCP/IP protocol stack corresponds to the OSI model's Application, Presentation, and Session layers and it provides the necessary services to support the applications running on the host, such as email, file transfer, and web browsing.