Which of the following approaches, given this company’…

You were just hired as a DevOps Engineer for a startup. Your startup uses AWS for 100% of their infrastructure. They currently have no automation at all for deployment, and they have had many failures while trying to deploy to production.
The company has told you deployment process risk mitigation is the most important thing now, and you have a lot of budget for tools and AWS resources.
Their stack:
2-tier API
Data stored in DynamoDB or S3, depending on type
Compute layer is EC2 in Auto Scaling Groups
They use Route53 for DNS pointing to an ELB
An ELB balances load across the EC2 instances
The scaling group properly varies between 4 and 12 EC2 servers. Which of the following approaches, given this company’s stack and their priorities, best meets the company’s needs?

A.
Model the stack in AWS Elastic Beanstalk as a single Application with multiple Environments. Use Elastic Beanstalk’s Rolling Deploy
option to progressively roll out application code changes when promoting across environments.

B.
Model the stack in 3 CloudFormation templates: Data layer, compute layer, and networking layer. Write stack deployment and
integration testing automation following Blue-Green methodologies.

C.
Model the stack in AWS OpsWorks as a single Stack, with 1 compute layer and its associated ELB. Use Chef and App Deployments
to automate Rolling Deployment.

D.
Model the stack in 1 CloudFormation template, to ensure consistency and dependency graph resolution. Write deployment and
integration testing automation following Rolling Deployment methodologies.