Which two layers of the OSI model are combined in the TCP/IP model's Network Access Layer?

The correct combination in the TCP/IP model's Network Access Layer consists of the Data Link Layer and the Physical Layer from the OSI model. This is because the Network Access Layer in the TCP/IP model encompasses the functions of both layers responsible for the physical transmission of data over a network.

The Data Link Layer is responsible for providing node-to-node data transfer, framing, and addressing within a single network segment. It deals with protocols that ensure error-free transmission of frames. On the other hand, the Physical Layer deals with the actual transmission of raw bit streams over a physical medium, including the electrical, optical, or radio signals utilized in the data communication.

By combining these two layers, the TCP/IP model simplifies the protocol stack by focusing on how data is transmitted across the network. This consolidation reflects practical networking approaches and allows the TCP/IP model to function effectively in various networking environments.

The other choices misidentify the correct layers or do not align with the specific functions represented in the TCP/IP model.