You have started a new job and are reviewing your company’s infrastructure on AWS You notice one web application where they have an Elastic Load Balancer (ELB) in front of web instances in an Auto Scaling Group. When you check the metrics for the ELB in CloudWatch you see four healthy instances in Availability Zone (AZ) A and zero in AZ B there are zero unhealthy instances. What do you need to fix to balance the instances across AZs?