Which two statements are true regarding BPDUs of spanning tree protocols? (Choose two.)
A.
Configuration BPDUs function as keepalives in STP and RSTP.
B.
BPDUs are sent by the designated bridge but not the backup bridge on shared segments.
C.
Configuration BPDUs are sent by both switches on point-to-point connections.
D.
Configuration BPDUs are not sent out interfaces configured as edge ports.