Amazon Web Services DOP-C02 Exam With Confidence Using Practice Dumps

The correct answer is C.

Option A is incorrect because using CloudWatch metrics to create a custom expression that identifies the CloudWatch log groups that have the most data being written to them is not a valid solution. CloudWatch metrics do not provide information about the size or volume of data being ingested by CloudWatch logs. CloudWatch metrics only provide information about the number of events, bytes, and errors that occur within a log group or stream. Moreover, creating a custom expression with CloudWatch metrics would require using the search_web tool, which is not necessary for this use case.

Option B is incorrect because using CloudWatch Logs Insights to create a set of queries for the application log groups to identify the number of logs written for a period of time is not a valid solution. CloudWatch Logs Insights can help analyze and filter log events based on patterns and expressions, but it does not provide information about the cost or billing of CloudWatch logs. CloudWatch Logs Insights also charges based on the amount of data scanned by each query, which could increase the logging costs further.

Option C is correct because using AWS Cost Explorer to generate a cost report that details the cost for CloudWatch usage is a valid solution. AWS Cost Explorer is a tool that helps visualize, understand, and manage AWS costs and usage over time. AWS Cost Explorer can generate custom reports that show the breakdown of costs by service, region, account, tag, or any other dimension. AWS Cost Explorer can also filter and group costs by usage type, which can help identify the specific CloudWatch log groups that are the source of the increased logging costs.

Option D is incorrect because using AWS CloudTrail to filter for CreateLogStream events for each application is not a valid solution. AWS CloudTrail is a service that records API calls and account activity for AWS services, including CloudWatch logs. However, AWS CloudTrail does not provide information about the cost or billing of CloudWatch logs. Filtering for CreateLogStream events would only show when a new log stream was created within a log group, but not how much data was ingested or stored by that log stream.

The question emphasizes “MOST securely” and involves a multi-account backup strategy with a centralized backup account. AWS Backup best practice for high-security environments is to use customer managed KMS keys for encrypting backup vaults rather than AWS managed keys. Customer managed keys provide tighter control over key lifecycle, key policies, and cross-account access.

Option A creates encrypted backup vaults in both the source and centralized accounts, each protected by a customer managed KMS key in that account. AWS Backup is then configured to create full EC2 backups (AMIs) and copy them to the centralized backup vault. This design ensures:

Encryption at rest in both accounts.

Independent key control and policies per account.

Secure cross-account backup copy behavior governed by explicit KMS key grants and vault access policies.

Option B incorrectly uses the source account’s KMS key to encrypt vaults in both accounts, which is not the recommended pattern; each account should manage its own CMK. Options C and D rely partially or fully on AWS managed keys, which are less appropriate when the requirement explicitly stresses maximum security and control.

Therefore, Option A best satisfies both the RPO/RTO goals (daily AMI backups with rapid restore) and the strongest encryption posture.