You are creating a solution to remove backup files older than 90 days from your backup Cloud Storage bucket. You want to optimize ongoing Cloud Storage spend. What should you do?

The correct answer is to write a lifecycle management rule in JSON and push it to the bucket with gsutil. Cloud Storage lifecycle management is designed for automating object management tasks, such as deleting old backups, and is the most cost-effective and efficient method. It natively handles the deletion based on age, reducing operational overhead. Writing a lifecycle management rule in XML is incorrect because Cloud Storage lifecycle rules are defined in JSON format, not XML. Scheduling a cron script using gsutil ls -lr or gsutil ls -l to find and remove items is inefficient and more complex to manage. While technically possible, it incurs additional compute costs for the cron job and requires manual scripting, which is prone to errors and less robust than native lifecycle management. Cloud Storage lifecycle management handles this natively and without additional compute charges.