CloudFormation modules are the best fit because the requirement is reusable, portable infrastructure configuration that can be shared across multiple AWS member accounts with low administrative overhead.
AWS describes CloudFormation modules as reusable resource configurations that can be included across stack templates in a repeatable and manageable way. This is stronger than nested stacks because modules are designed as standardized building blocks and can be published and versioned through the CloudFormation registry. CDK is powerful, but option A only stores source code and does not provide a registry-based sharing mechanism. AWS SAM is focused on serverless applications and is not the cleanest fit for EKS, FSx for Lustre, and S3 infrastructure patterns.

To meet the requirements, the DevOps engineer should do the following:
Turn on the Multi-AZ option on the Aurora cluster.
Update the application to use the Aurora cluster endpoint for write operations.
Update the Aurora cluster's reader endpoint for reads.
Turning on the Multi-AZ option will create a replica of the database in a different Availability Zone. This will ensure that the database remains available even if one of the Availability Zones is unavailable.
Updating the application to use the Aurora cluster endpoint for write operations will ensure that all writes are sent to both the primary and replica databases. This will ensure that the data is always consistent.
Updating the Aurora cluster's reader endpoint for reads will allow the application to read data from the replica database. This will improve the performance of the application during the maintenance window.

The correct answer is C. Configuring AWS CloudTrail to send log data events to an Amazon CloudWatch Logs log group and creating a CloudWatch logs metric filter to match failed ConsoleLogin events is the simplest and most efficient way to monitor and alert on failed login attempts. Creating a CloudWatch alarm that is based on the metric filter and configuring an alarm action to send messages to the SNS topic will ensure that the security team is notified when multiple failed login attempts occur. This solution requires the least operational effort compared to the other options.
Option A is incorrect because it involves configuring AWS CloudTrail to send log management events instead of log data events. Log management events are used to track changes to CloudTrail configuration, such as creating, updating, or deleting a trail. Log data events are used to track API activity in AWS accounts, such as login attempts. Therefore, option A will not capture the failed ConsoleLogin events.
Option B is incorrect because it involves creating an Amazon Athena query and two Amazon EventBridge rules to monitor and alert on failed login attempts. This is a more complex and costly solution than using CloudWatch logs and alarms. Moreover, option B relies on the query returning a failure, which may not happen if the query is executed successfully but does not find any failed logins.
Option D is incorrect because it involves configuring AWS CloudTrail to send log data events to an Amazon S3 bucket and configuring an Amazon S3 event notification for the s3:ObjectCreated event type. This solution will not work because the s3:ObjectCreated event type does not allow filtering by ConsoleLogin failed events. The event notification will be triggered for any object created in the S3 bucket, regardless of the event type. Therefore, option D will generate a lot of false positives and unnecessary notifications.
AWS CloudTrail Log File Examples
Creating CloudWatch Alarms for CloudTrail Events: Examples
Monitoring CloudTrail Log Files with Amazon CloudWatch Logs

By default, the AWSCodeCommitPowerUser managed policy allows users to push changes to any branch in any repository in the AWS account. To restrict the developers' ability to push changes to the main branch directly, an additional policy is needed that explicitly denies these actions for the main branch.
The Deny rule should be included in a policy statement that targets the specific repositories and includes a condition that references the main branch. The policy statement should look something like this:
{
"Effect": "Deny",
"Action": [
"codecommit:GitPush",
"codecommit:PutFile"
],
"Resource": "arn:aws:codecommit:<region>:<account-id>:<repository-name>",
"Condition": {
"StringEqualsIfExists": {
"codecommit:References": [
"refs/heads/main"
]
}
}