Which of the following protocols is likely found at Layer 7 of the OSI model?

• A. IP
• B. TCP
• C. SMTP
• D. FTP

Answer: (C)

SMTP, or Simple Mail Transfer Protocol, is indeed associated with Layer 7 of the OSI model, which is the application layer. This layer is where end-user software operates, and it facilitates communication between different software applications over a network.

SMTP specifically is used for sending emails from a client to a server or between servers. It defines the communication rules for how email messages are sent and received, making it a crucial protocol for email applications.

The other protocols mentioned function at different layers of the OSI model. IP (Internet Protocol) operates at Layer 3 (Network layer), managing the routing of packets across network boundaries. TCP (Transmission Control Protocol) functions at Layer 4 (Transport layer), ensuring reliable data transmission between hosts. FTP (File Transfer Protocol), while also an application-layer protocol, is not the primary focus here because the question specifically identifies SMTP as the protocol associated with Layer 7 among the given options.