Which three protocols are considered application layer protocols within the TCP/IP protocol suite?

The correct answer highlights three protocols that operate at the application layer of the TCP/IP protocol suite: DHCP, DNS, and FTP. These protocols are specifically designed for communication and data exchange between software applications over a network.

Dynamic Host Configuration Protocol (DHCP) is used to assign dynamic IP addresses to devices on a network, enabling them to communicate without requiring manual configuration. Domain Name System (DNS) translates user-friendly domain names into IP addresses, allowing users to access websites without needing to remember numerical addresses. File Transfer Protocol (FTP) is a standard network protocol used to transfer files between client and server over TCP/IP.

In contrast, the other choices contain protocols that do not operate solely at the application layer. For example, HTTP and SMTP, while they are application layer protocols, are paired with IP in one option where this demonstrates that IP is actually a network layer protocol. In another option, TCP and UDP are transport layer protocols, while ICMP is primarily for network layer diagnostics. Lastly, ARP is a protocol that helps map IP addresses to MAC addresses, functioning at the link layer rather than the application layer. Thus, the selection of DHCP, DNS, and FTP accurately reflects protocols that operate at the application layer, fulfilling the question’s requirements.