How should a database specialist achieve this task?
Turn off the Multi-AZ feature, add the read replica, and turn Multi-AZ back on again.
Set the backup retention period to 0, add the read replica, and set the backup retention period to 7 days again.
Restore a snapshot to a new RDS DB instance and add the DB instance as a replica to the original database.
Add the new read replica without making any other changes to the RDS database.
Explanations:
Turning off Multi-AZ is not required for adding a read replica. Multi-AZ configuration is for high availability, while read replicas are used for scaling read operations. These two features can coexist.
Changing the backup retention period to 0 is not necessary for adding a read replica. The backup retention period setting does not affect the ability to create a read replica.
Restoring a snapshot to create a new DB instance and then adding it as a replica is an unnecessary step. Read replicas can be created directly from an existing RDS DB instance without the need to restore from a snapshot.
You can add a read replica to an RDS DB instance without needing to make any other changes. The Multi-AZ feature and automatic backups do not prevent you from creating a read replica.
I gauge that the answer is:
Add the new read replica without making any other changes to the RDS database.