What should the solutions architect do to reduce the overall data transfer costs?
Place all the EC2 instances in an Auto Scaling group.
Place all the EC2 instances in the same AWS Region.
Place all the EC2 instances in the same Availability Zone.
Place all the EC2 instances in private subnets in multiple Availability Zones.
Explanations:
Placing EC2 instances in an Auto Scaling group does not directly address data transfer costs. Auto Scaling focuses on managing capacity.
Placing EC2 instances in the same AWS Region reduces latency and potential inter-region data transfer costs, but doesn’t eliminate all transfer costs.
Placing EC2 instances in the same Availability Zone helps avoid inter-AZ data transfer costs, which are charged higher than within the same AZ.
Placing EC2 instances in multiple Availability Zones would increase inter-AZ data transfer costs, making it less cost-effective than within a single AZ.
As I recall, the answer is:
Place all the EC2 instances in the same Availability Zone.