Which protocol automatically assigns IP addresses to devices on a network?

The correct choice is DHCP, which stands for Dynamic Host Configuration Protocol. This protocol is designed to automatically assign IP addresses to devices on a network, simplifying the process of connecting devices without the need for manual configuration. When a device joins a network, it sends a request for an IP address to the DHCP server, which then assigns an available IP address from a predetermined range. This process also includes providing other essential network configuration data, such as the default gateway and DNS server information, allowing the device to communicate effectively on the network.

In contrast, DNS (Domain Name System) is primarily concerned with translating human-friendly domain names into IP addresses, rather than assigning IP addresses to devices. HTTP (HyperText Transfer Protocol) is used for transmitting web pages over the internet, and FTP (File Transfer Protocol) is used for transferring files between computers on a network. Neither DNS, HTTP, nor FTP are involved in the automatic assignment of IP addresses, which is why they do not fit in this context.