How can this be automated with the LEAST amount of operational overhead?

A company has deployed several applications globally. Recently, Security Auditors found that few Amazon EC2 instances were launched without Amazon EBS disk encryption. The Auditors have requested a report detailing all EBS volumes that were not encrypted in multiple AWS accounts and regions. They also want to be notified whenever this occurs in future.

How can this be automated with the LEAST amount of operational overhead?
A . Create an AWS Lambda function to set up an AWS Config rule on all the target accounts. Use AWS Config aggregators to collect data from multiple accounts and regions. Export the aggregated report to an Amazon S3 bucket and use Amazon SNS to deliver the notifications.
B. Set up AWS CloudTrail to deliver all events to an Amazon S3 bucket in a centralized account. Use the S3 event notification feature to invoke an AWS Lambda function to parse AWS CloudTrail logs whenever logs are delivered to the S3 bucket. Publish the output to
an Amazon SNS topic using the same Lambda function.
C. Create an AWS CloudFormation template that adds an AWS Config managed rule for EBS encryption. Use a CloudFormation stack set to deploy the template across all accounts and regions. Store consolidated evaluation results from config rules in Amazon S3. Send a notification using Amazon SNS when non- compliant resources are detected.
D. Using AWS CLI, run a script periodically that invokes the aws ec2 describe-volumes query with a JMESPATH query filter. Then, write the output to an Amazon S3 bucket. Set up an S3 event notification to send events using Amazon SNS when new data is written to the S3 bucket.

View Answer

Answer: C

Explanation:

https://aws.amazon.com/blogs/aws/aws-config-update-aggregate-compliance-data-across-accounts-regions/

https://docs.aws.amazon.com/config/latest/developerguide/aws-config-managed-rules-cloudformation-templates.html