A. Launch the application from the CloudFormation template in the second region, which sets the capacity of the Auto Scaling group to 1. Create an Amazon RDS read replica in the second region. In the second region, enable cross-region replication between the original S3 bucket and a new S3 bucket. To fail over, promote the read replica as master. Update the CloudFormation stack and increase the capacity of the Auto Scaling group.
B. Launch the application from the CloudFormation template in the second region, which sets the capacity of the Auto Scaling group to 1. Create a scheduled task to take daily Amazon RDS cross-region snapshots to the second region. In the second region, enable cross-region replication between the original S3 bucket and Amazon Glacier. In a disaster, launch a new application stack in the second region and restore the database from the most recent snapshot.
C. Launch the application from the CloudFormation template in the second region, which sets the capacity of the Auto Scaling group to 1. Use Amazon CloudWatch Events to schedule a nightly task to take a snapshot of the database, copy the snapshot to the second region, and replace the DB instance in the second region from the snapshot. In the second region, enable cross-region replication between the original S3 bucket and a new S3 bucket. To fail over, increase the capacity of the Auto Scaling group.
D. Use Amazon CloudWatch Events to schedule a nightly task to take a snapshot of the database and copy the snapshot to the second region. Create an AWS Lambda function that copies each object to a new S3 bucket in the second region in response to S3 event notifications. In the second region, launch the application from the CloudFormation template and restore the database from the most recent snapshot.