At which layer of the OSI model is the routing information processed?

The correct answer is based on the OSI model's structure and the functions associated with each layer. Routing information is processed at Layer 3, also known as the Network layer.

This layer is responsible for logical addressing and routing, which involves determining the best path for data packets to travel across networks. Devices such as routers operate at this layer, using routing protocols to exchange information about the paths available for data transmission. The protocols at Layer 3, like IP (Internet Protocol), help in not only addressing but also in making routing decisions based on the network topology.

Other layers, such as Layer 1 (Physical) and Layer 2 (Data Link), deal with issues related to the physical transmission of data and framing of data packets, respectively. Layer 4 (Transport) is focused on end-to-end communication services and does not directly deal with routing. Thus, it is clear that Layer 3 is the appropriate layer for the processing of routing information in the OSI model.