Which two statements are correct regarding Flex Links?

Which two statements are correct regarding Flex Links? (Choose two)

A.
An interface can belong to multiple 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