What happens in the event the Load Balancer has a failure ?

A vSphere administrator deployed an NSX Edge Load Balancer in High Availability (HA) mode.
What happens in the event the Load Balancer has a failure ?

A.
The secondary NSX Edge Load Balancer assumes the role of primary. Existing Flows will need to have
their connections reestablished.

B.
HA will start the NSX Edge Load Balancer on another ESXi host in the cluster. All existing flows will
need to have their connections reestablished.

C.
HA will start the NSX Edge Load Balancer on another ESXi host in the cluster. The NSX Controller
caches existing flows and hands them to the Load Balancer when it is back up.

D.
The secondary NSX Edge Load Balancer assumes the role of primary. The NSX Controller caches
existing flows and hands them to the Load Balancer when it is back up.