Which two statements about BFD are correct? (Choose two)

Which two statements about BFD are correct? (Choose two)
A . BFD provides link failure detection for static routes.
B . BFD modifies each protocol timer to improve link failure detection.
C . NSR maintains BFD sessions during Routing Engine switchover.
D . GRES is required for BFD sessions to be established.

Answer: A, C

Explanation:

https://www.juniper.net/documentation/en_US/junos/topics/topic-map/policy-bfd-static-routes.html

https://www.juniper.net/documentation/en_US/junos/topics/reference/requirements/nsr-systemrequirements.html#section-nonstop-routing-bfd-support