A member of the Security Audit team would like to perform an analysis and investigation of ELB Access Logs by doing some ad-hoc queries. The ELB Access Logging is enabled. Which solution enables the team members to perform Access Logs analysis most efficiently?

Answer options:

A.CloudTrail
B.Athena
C.QuickSight
D.Redshift
E.Splunk

Answer: B
Option A is incorrect because CloudTrail manages API activity on our AWS account and keeps a log of it. It cannot be used to query ELB Access Logs.
Option B is CORRECT because Amazon Athena supports S3 as a data source and can be used to query data directly in S3. Athena can be worked on using ad-hoc queries and can perform access logs analytics efficiently.
Option C is incorrect because QuickSight only supports text file formats (.csv, .tsv, .clf, or .elf) stored in S3.ELB Access Logs are compressed files. AWS QuickSight is used for visualization and would not be useful with ad-hoc queries and performing analytics on ELB access logs.
Option D is incorrect because using Redshift would not be the most efficient solution as it requires the provisioning of infrastructure and ETL of data into the service.
Option E is incorrect because it is not the most efficient solution. Splunk is a third-party solution. So it requires purchasing of licenses, provisioning of infrastructure, installation and configuration, and ETL of data.
Reference:
https://docs.aws.amazon.com/athena/latest/ug/application-load-balancer-logs.html