The correct answer is: C. Application
The application layer is the highest layer of the OSI model. It is responsible for providing services to the user, such as file transfer, email, and web browsing. The application layer interacts with the user through a variety of applications, such as web browsers, email clients, and file transfer programs.
The session layer is responsible for managing the communication between two applications. It provides a way for applications to establish, maintain, and terminate a connection. The session layer is not directly involved in the user interface.
The data-link layer is responsible for transferring data between two nodes on a network. It provides a reliable way for data to be transmitted, even in the presence of errors. The data-link layer does not interact with the user.
The network layer is responsible for routing data between networks. It provides a way for data to be forwarded from one network to another. The network layer does not interact with the user.
The physical layer is responsible for transmitting data over a physical medium, such as a cable or a wireless link. It provides a way for data to be converted into a form that can be transmitted over the physical medium. The physical layer does not interact with the user.