The network layer is concerned with __________ of data.c) packets d) bytesa) bits b) frames

The correct answer is c) packets.

Explanation:

The network layer is primarily responsible for the routing of data across different networks and it operates on the concept of packets. In the context of the OSI (Open Systems Interconnection) model, each layer has its own specific responsibilities. The network layer, which is the third layer, focuses on the delivery of packets from the source to the destination across multiple networks.

In terms of data encapsulation:

1. Data at the application layer is typically referred to as messages.
2. When this data is passed down to the transport layer, it is encapsulated into segments (for TCP) or datagrams (for UDP).
3. As it moves to the network layer, these segments/datagrams are then converted into packets including the necessary headers that contain routing information needed for the next hop towards their final destination.

Thus, when considering what the network layer is concerned with, the most appropriate choice from the options is packets. Other terms like bytes, bits, and frames relate to different layers; bytes are typically a data measure, bits are the fundamental unit of data, and frames are more relevant to the data link layer which encapsulates packets into frames for transmission over the physical network.