Which the following events can trigger the election of a new primary unit in a HA cluster? (Choose two.)

Which the following events can trigger the election of a new primary unit in a HA cluster? (Choose two.)
A . Primary unit stops sending HA heartbeat keepalives.
B . The FortiGuard license for the primary unit is updated.
C . One of the monitored interfaces in the primary unit is disconnected.
D . A secondary unit is removed from the HA cluster.

Answer: A,C