Which statement describes a function of the LLC sublayer?

• A. It places information in the frame allowing multiple Layer 3 protocols to use the same network interface and media.
• B. It provides the physical layer signaling.
• C. It handles IP routing between networks.
• D. It defines user application interfaces.

Answer: (A)

The function being described is how the LLC sublayer lets different network-layer protocols share the same data-link and media. LLC inserts control information into the frame so the receiving station can identify which Layer 3 protocol the payload belongs to, enabling multiplexing of multiple protocols (such as IP and others) over a single network interface. This separation allows the data-link layer to carry diverse higher-layer protocols without needing separate physical links. The physical layer is responsible for signaling on the medium, not LLC. Routing between networks happens at the network layer with routers, not the LLC, and defining user application interfaces belongs to higher layers, not the LLC.