Which layer of the networking model includes Ethernet?

The Network Access layer, also known as the Link layer, is responsible for the physical transmission of data over a network. It encompasses protocols and technologies that effectively manage access to the physical medium, including how data is framed, transmitted, and received. Ethernet is a key protocol that operates at this layer, detailing how data packets are created, addressed, transmitted, and received over a local area network (LAN).

In this context, Ethernet defines how devices on the same network segment communicate with each other through physical and data link protocols, ensuring data packets are correctly formed and sent across the wires or via wireless connections.

The other layers listed do not pertain to Ethernet's function. The Application layer deals with software applications and user interfaces, the Transport layer handles end-to-end communication and reliability, and the Internet layer manages logical addressing and routing of data between networks. Therefore, the Network Access layer is specifically where Ethernet operates, making it the correct answer.