An Application Uses an Amazon RDS MySQL DB Instance

An application uses an Amazon RDS MySQL DB instance. The RDS database is becoming low on disk space. A solutions architect wants to increase the disk space without downtime. Which solution meets these requirements with the LEAST amount of effort?

A) Enable storage auto scaling in RDS.
B) Increase the RDS database instance size.
C) Change the RDS database instance storage type to Provisioned IOPS.
D) Back up the RDS database, increase the storage capacity, restore the database and stop the previous instance.