A single packet on a data link is known as

The correct answer is: B. Frame

A frame is a single packet on a data link. It is a unit of data that is transmitted between two nodes on a data link. A frame consists of a header, a payload, and a trailer. The header contains control information, such as the source and destination addresses. The payload contains the actual data to be transmitted. The trailer contains error-checking information.

The other options are incorrect because:

• A path is a route between two nodes.
• A block is a unit of data that is larger than a frame.
• A group is a collection of frames.

I hope this helps! Let me know if you have any other questions.