The correct answer is D. Categorization Mode in HTTPS-related handling allows the gateway to make a category decision using information available before full decryption, such as the destination domain, SNI/certificate attributes, and reputation/category lookup. The purpose is classification, not full content inspection. Option A is incomplete because trusted-site bypass is handled with bypass rules, bypass lists, or policy exceptions, not by Categorization Mode alone. Option B is wrong because categorization does not mean decrypting all HTTPS traffic by default. Option C is also wrong because the mode is not a blanket block action against encrypted traffic. This distinction matters because Application Control and URL Filtering frequently need to decide whether a site should be allowed, blocked, or bypassed before content is inspected. Full HTTPS Inspection decrypts traffic for supported blades, whereas categorization can classify traffic based on metadata and certificate/domain details. Reference topics: HTTPS Inspection, URL Filtering categorization, certificate/domain-based HTTPS handling, encrypted traffic policy decisions.