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 a point-to-point link for an effective loop prevention mechanism
B . Configure loop guard on a PortFast-enable port to ensure optimal loop prevention mechanism
C . Configure loop guard when root guard is enabled for optimal loop prevention mechanism
D . Configure loop guard to prevent root port from becoming a designated port
E . Configure loop guard on root port to help detect and isolate unidirectional link failure

Answer: AD