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. The SAK is secured by 128 bit AES-GCM by default
C. When switch-to-switch link security is configured in manual mode, the SAP operation mode must be set to GCM
D. MACsec is not supported in MDA mode.
E. MKA heartbeats are sent at a default interval of 3 seconds.