Flex Links are a pair of a Layer 2 interfaces (switchports or port channels), where one interface is configured to act as a backup to the other. Which two statements are correct regarding Flex Links?（）

• A、An interface can only belong to single Flex Links.
• B、An interface can belong to multiple Flex Links.
• C、Flex Links operate only over single pairs of links.
• D、Flex Links automatically disable STP so no BPDUs are propagated.