How does the ProxySG primarily differentiate between file types?

The ProxySG differentiates between file types primarily by using a combination of methods, which is why this option is the correct answer. This multifaceted approach includes examining the file extension, the HTTP content type specified in requests, and the apparent data type derived from the actual content of the file being transmitted.

Utilizing just the file extension alone can lead to inaccuracies, as file extensions can be misleading or incorrect. Similarly, relying solely on the HTTP content type may not always provide enough detail, as it can sometimes be improperly set or omitted. Apparent data type checking involves analyzing the content itself, allowing for more accurate identification and classification.

This comprehensive methodology ensures that the ProxySG can effectively manage and filter traffic based on the specific type of files being processed, improving security and content management capabilities within a network environment.