Which layer is responsible for error detection and correction?

The layer responsible for error detection and correction is the Data Link Layer. This layer provides the means for the physical transmission of data and is critical for ensuring that the data sent over a network arrives accurately and without errors. It achieves this through various techniques, such as checksums, CRC (Cyclic Redundancy Check), and acknowledgment packets, which help verify the integrity of the data frames being transmitted.

By detecting errors that may occur during transmission, the Data Link Layer ensures reliable communication between directly connected nodes. If an error is detected, it can trigger resend requests to correct the error, ensuring a consistent and reliable flow of information.

In contrast, the Transport Layer primarily focuses on end-to-end communication, including flow control and overall data integrity in terms of segmenting data and ensuring the proper protocols are followed, but it doesn't handle direct error correction on the same level as the Data Link Layer. The Session Layer manages sessions between applications and does not deal specifically with error detection. Lastly, the Application Layer is responsible for providing network services directly to end-users and does not perform error detection or correction at the data transport level.

Thus, the Data Link Layer's role in monitoring and correcting potential transmission errors positions it as the correct choice in this context.