Q1. An AWS CloudFormation stack update fails with a "Resource is in use" error on an Amazon RDS multi-AZ instance. The update requires changing the instance class to a larger size. What is the best multi-step procedure to safely update the stack without causing downtime or data loss?

• ○Create a read replica, promote it to master, update the stack to point to the new instance, then delete the old instance.
• ○Modify the RDS instance class directly in the AWS console, then update the CloudFormation stack with the new class.
• ○Perform a snapshot backup, delete the RDS instance, update the stack with the new instance class, then restore from the snapshot.
• ○Use CloudFormation stack update with the UpdatePolicy attribute to apply the instance class change with minimal downtime.