Which three statements are true about the spanning-tree loop guard feature? (Choose three.)
A. Loop guard affects UplinkFast operation.
B. Loop guard can be enabled on PortFast ports.
C. Loop guard operation is not affected by the spanning-tree timers.
D. Loop guard must be enabled on point-to-point link only.
E. Loop guard cannot be enabled on a switch that also has root guard enabled.
F. Loop guard can detect a unidirectional link.
