Compression of data to reduce transmission size is performed at the:

Compression reduces the amount of data that needs to be sent. This helps in saving bandwidth and speeding up the transmission process, especially for large files such as videos, images, and documents.

Main functions of the Presentation Layer include:

• Data Compression: Shrinks the size of data to reduce transmission time and bandwidth usage.


• Data Encryption/Decryption: Secures the data by converting it into a safe format before transmission and restoring it after receiving.


• Data Translation: Converts data from one format to another (e.g., character sets like ASCII to EBCDIC).

This layer acts as a translator between different systems. It ensures that the data sent by one system can be correctly understood and displayed by the receiving system.

Conclusion: The correct answer is Presentation Layer, as it handles important tasks like compression, encryption, and data formatting to prepare information for the application layer or network transmission.