What is the primary function of the Data Link Layer (Layer 2) in the OSI model?

Correct answer: Switching frames between ports on the same network segment

Option C is correct because the Data Link Layer (Layer 2) is responsible for node-to-node delivery of frames within the same network segment, using MAC addresses to switch or forward frames between ports on a local network, which is the core function of Ethernet switches. Option A is incorrect because encryption is not a function defined at Layer 2; it is typically handled at higher layers such as the Presentation Layer (Layer 6) or through protocols like TLS at the Transport and Application layers. Option B is incorrect because routing packets across networks using logical addresses such as IP addresses is the function of the Network Layer (Layer 3), not Layer 2. Option D is incorrect because establishing end-to-end connections is a function of the Transport Layer (Layer 4), which manages session setup, reliability, and flow control between communicating hosts.