Which of the following is considered a network layer protocol?

The Internet Protocol is considered a network layer protocol because it is responsible for the addressing and routing of packets across networks. Specifically, it facilitates the sending and receiving of data over the internet by handling the logical addressing of devices through IP addresses. This allows data packets to be directed to their intended destinations across multiple interconnected networks.

In contrast, the other protocols serve different layers in the OSI model. The Hypertext Transfer Protocol operates at the application layer, enabling the transfer of hypertext documents over the internet. The Address Resolution Protocol functions at the data link layer and is used to map an IP address to a physical machine address (MAC address) necessary for local network communications. Lastly, the File Transfer Protocol also operates at the application layer, providing a standard way for transferring files between systems over the internet. Thus, by fulfilling its role in managing network communications, the Internet Protocol distinctly qualifies as a network layer protocol.