Which OSI layer is responsible for adding frame delimiters and addressing within a LAN?

• A. Data Link Layer
• B. Network Layer
• C. Transport Layer
• D. Application Layer

Answer: (A)

The Data Link layer handles framing and local addressing. It takes packets from the Network layer and encapsulates them into frames with a header that includes the destination and source MAC addresses, plus a trailer with error-checking information. This layer is also responsible for framing boundaries and how devices on the same LAN access the medium. In a LAN, delivery is based on MAC addresses, while IP addresses are used by the Network layer for routing between networks. The Transport and Application layers handle end-to-end reliability and user-facing communications, not local frame delimitation.