AWS CloudTrail Lake is purpose-built to store, query, and analyze CloudTrail events, including data events, without requiring additional infrastructure. The AWS Certified Security – Specialty documentation explains that CloudTrail Lake provides immutable event storage with configurable retention periods, including multi-year retention, which satisfies long-term compliance requirements such as 7-year retention. Events are stored in an append-only, immutable format managed by AWS, reducing operational complexity.

CloudTrail Lake supports SQL-based queries for complex analysis directly against the event data, eliminating the need to export logs to other services for querying. Additionally, CloudTrail Lake includes built-in dashboards and integrations that enable visualization of event trends and patterns without standing up separate analytics or visualization platforms.

Option B is invalid because CloudTrail Event History only retains events for up to 90 days and does not support long-term retention or advanced querying. Option C introduces high operational overhead and cost by requiring persistent Amazon EMR clusters and additional services. Option D incurs ongoing ingestion, indexing, and storage costs for OpenSearch Service over a 7-year period, making it less cost-effective than CloudTrail Lake.

AWS documentation positions CloudTrail Lake as the most cost-effective and operationally efficient solution for long-term, queryable CloudTrail event storage and visualization.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

AWS CloudTrail Lake Architecture and Retention

AWS CloudTrail Data Events Overview