Which of the following statements best describes the function of the data link layer?

The data link layer is responsible for defining how data packets are framed for transmission over a physical medium. Specifically, it takes the Protocol Data Units (PDUs) from the network layer (Layer 3) and packages them into frames, which include not only the data but also headers and trailers that contain control information such as source and destination MAC addresses. This framing is crucial for ensuring that the data can be correctly interpreted and routed over the underlying physical network, allowing for reliable communication between devices on the same local network.

The data link layer also handles error detection and correction, as well as flow control, which ensures that the data is sent and received accurately and efficiently. By delivering this functionality, the data link layer acts as a bridge between the physical layer and the network layer, facilitating communication within the local area network while ensuring that the data is properly formatted for transmission. Thus, packaging Layer 3 PDUs into frame format for transmission is the primary and defining role of the data link layer.