Which two statements are true of loop guard? (Choose two.)

Which two statements are true of loop guard? (Choose two.)
A . Configure loop guard on root port to help detect and isolate unidirectional link failure
B . Configure loop guard when root guard is enabled for optimal loop prevention mechanism
C . Configure loop guard on a PortFast-enabled port to ensure optimal loop prevention mechanism.
D . Configure loop guard on a point-to-point link for an effective loop prevention mechanism
E . Configure loop guard to prevent root port from becoming a designated port

Answer: DE