You have a high-volume 'Audit logs' table where entries only need to persist for 90 days. What is the most cost-effective way to manage this?

1. A Run a nightly scheduled Lambda function that scans and deletes old rows.
2. B Enable TTL on a timestamp attribute; DynamoDB will automatically delete expired items in the background at no extra RCU/WCU cost.
3. C Delete the entire table and recreate it every 3 months.
4. D Manually delete items via the AWS Console when the storage bill gets too high.