Answer: Set up an S3 Lifecycle policy to transition objects to S3 Glacier Deep Archive after 2 years.

## Explanation **Correct Answer: B** **Why Option B is correct:** 1. **Data from the most recent 2 years must be highly available and immediately retrievable** - This means data less than 2 years old should remain in S3 Standard (which provides immediate retrieval). 2. **Data must be kept for at least 25 years** - This is a long-term retention requirement. 3. **S3 Glacier Deep Archive** is designed for long-term data retention (minimum 180 days storage duration) with retrieval times of 12-48 hours, making it cost-effective for archival data. 4. **Transitioning after 2 years** ensures that recent data (0-2 years) stays in S3 Standard for immediate access, while older data (2+ years) moves to Glacier Deep Archive for cost savings. **Why other options are incorrect:** **Option A:** Transitioning to Glacier Deep Archive immediately would violate the requirement for immediate retrievability of data from the most recent 2 years, as Glacier Deep Archive has 12-48 hour retrieval times. **Option C:** S3 Intelligent-Tiering with archiving option automatically moves data between access tiers, but it doesn't provide the precise 2-year control needed. The archiving option moves data to Glacier Deep Archive after 90 days of no access, which doesn't align with the 2-year requirement. **Option D:** Transitioning to S3 One Zone-IA immediately would reduce costs but: - S3 One Zone-IA stores data in only one Availability Zone, which doesn't provide the same durability as S3 Standard (which stores data across multiple AZs) - The requirement states data must be "highly available" for the first 2 years, and S3 One Zone-IA has lower availability (99.5% vs 99.99% for S3 Standard) - It still transitions to Glacier Deep Archive after 2 years, but the immediate transition to One Zone-IA violates the high availability requirement **Key AWS Concepts:** - **S3 Lifecycle policies** automate transitioning objects between storage classes based on age - **S3 Standard** provides immediate access, high durability (99.999999999%), and high availability (99.99%) - **S3 Glacier Deep Archive** is the lowest-cost storage class for long-term archival with retrieval times of 12-48 hours - **Retention requirements** dictate when data should be moved to more cost-effective storage classes

Author: LeetQuiz Editorial Team