FortiGate SD-WAN uses traffic-classification criteria to identify application flows and apply appropriate forwarding strategies based on business priorities and link-performance requirements.

Option C is correct because application categories can be used to identify traffic belonging to defined application groups. This capability enables administrators to steer business-critical applications through preferred WAN paths while directing less-sensitive traffic through alternative links.

Application-aware SD-WAN rules can use FortiGuard application identification to make forwarding decisions without relying exclusively on destination IP addresses or transport ports.

Option D is correct because the Internet Service Database provides predefined classifications for cloud services and internet applications. FortiGate can use ISDB objects in SD-WAN service rules to steer traffic toward destinations associated with services such as Microsoft 365 and other cloud applications.

Option A is incorrect because physical interface type is not one of the application or destination matching criteria represented by this question. SD-WAN members identify eligible forwarding interfaces, which is distinct from the traffic-classification criteria.

Option B is incorrect because BGP attributes influence routing decisions and route selection but are not directly equivalent to the application and ISDB matching criteria used by these service rules.

Together, application-category and ISDB matching provide granular, application-aware steering.