Which two statements are correct regarding Flex Links? CareerCert

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? CareerCert.blogspot.com

A.
An interface can only belong to single Flex Links.

B.
Flex Links operate only over single pairs of links.

C.
Flex Link pairs must be of the same interface type.

D.
Flex Links automatically disable STP so no BPDUs are propagated.

E.
Failover from active to standby on Flex Links takes less than a second.