Explanation: The Link layer, also known as the Data Link layer (Layer 2) of the OSI model, is precisely where bits are organized into frames. This layer handles node-to-node data transfer, adding headers and trailers to the raw bits for error detection and correction, and managing access to the physical medium (e.g., controlling when a packet radio can transmit). It ensures reliable data transmission across a physical link by controlling data flow and detecting errors. The Transport layer (A) provides end-to-end communication services between applications, focusing on reliability and flow control between hosts, not individual bits and frames. "Communications layer" (C) and "Synchronization layer" (D) are not standard layer names within the seven-level International Organization for Standardization's OSI reference model. While synchronization is a key function, it's typically managed within the Physical and Link layers, not as a distinct layer.