A finance company needs to make sure that its MySQL database backups are available for the most recent 90 days. All of the MySQL databases are hosted on Amazon RDS for MySQL DB instances. A database specialist must implement a solution that meets the backup retention requirement with the least possible development effort.
Which approach should the database specialist take?

A. Use AWS Backup to build a backup plan for the required retention period. Assign the DB instances to the backup plan.
B. Modify the DB instances to enable the automated backup option. Select the required backup retention period.
C. Automate a daily cron job on an Amazon EC2 instance to create MySQL dumps, transfer to Amazon S3, and implement an S3 Lifecycle policy to meet the retention requirement.
D. Use AWS Lambda to schedule a daily manual snapshot of the DB instances. Delete snapshots that exceed the retention requirement.