A list of Availability Zones. At least one Availability Zone must be specified. Specified Availability Zones must be in the same EC2 Region as the load balancer. Traffic will be equally distributed across all zones. You can later add more Availability Zones after the creation of the load balancer by calling EnableAvailabilityZonesForLoadBalancer action.

public List<string> AvailabilityZones { get; set; }