Which two statements about the MACsec security protocol are true? (Choose two.)

Which two statements about the MACsec security protocol are true? (Choose two.)
A . Stations broadcast an MKA heartbeat that contains the key server priority.
B . MACsec is not supported in MDA mode.
C . When switch-to-swltch link security is configured In manual mode, the SAP operation mode must be set to GC
E . The SAK is secured by 128-bit AES-GCM by default.
F . MKA heartbeats are sent at a default interval of 3 seconds.

Answer: AD