AWS Certified Solutions Architect – Associate (SAA-C02) — Question 181

A solutions architect is creating an application that will handle batch processing of large amounts of data. The input data will be held in Amazon S3 and the output data will be stored in a different S3 bucket. For processing, the application will transfer the data over the network between multiple Amazon EC2 instances.
What should the solutions architect do to reduce the overall data transfer costs?

Answer options

• A. Place all the EC2 instances in an Auto Scaling group.
• B. Place all the EC2 instances in the same AWS Region.
• C. Place all the EC2 instances in the same Availability Zone.
• D. Place all the EC2 instances in private subnets in multiple Availability Zones.

Correct answer: C

Explanation

Choosing option C, placing all EC2 instances in the same Availability Zone, reduces data transfer costs because intra-zone data transfer is typically cheaper than inter-zone transfer. Options A and B do not specifically address data transfer costs, and option D may increase costs due to cross-AZ data transfer fees.