Which service is described as part of the data link layer?

• A. It manages the access of frames to the network media.
• B. It defines the end-to-end delivery addressing scheme.
• C. It determines the path packets take through the network.
• D. It provides reliable delivery through link establishment and flow control.

Answer: (A)

The data link layer is responsible for node-to-node data transfer and, crucially, how frames gain access to the physical medium. This includes media access control, which determines who can send frames on the network media at any given time and how collisions are avoided or managed in shared networks. That is exactly what the option describes.

End-to-end addressing and path determination belong to the network layer and routing, which decide how to address devices across the entire path and which route packets take. Providing reliable delivery through link establishment and flow control touches on data link concepts but is often associated with ensuring reliability across a link or with the transport layer’s responsibilities; the media-access aspect is the clearest data link service.