You have been asked to leverage Amazon VPC BC2 and SOS to implement an application that submits and
receives millions of messages per second to a message queue. You want to ensure your application has
sufficient bandwidth between your EC2 instances and SQS
Which option will provide the most scalable solution for communicating between the application and SQS?

A.
Ensure the application instances are properly configured with an Elastic Load Balancer

B.
Ensure the application instances are launched in private subnets with the EBS-optimized option enabled

C.
Ensure the application instances are launched in public subnets with the associate-public-IP-address=true
option enabled

D.
Launch application instances in private subnets with an Auto Scaling group and Auto Scaling triggers
configured to watch the SQS queue size

Explanation:
http://www.cardinalpath.com/autoscaling-your-website-with-amazon-web-services-part-2/