SAA-C03 practice - PrepKeys

Q5 Single choice

A company runs a production application on a fleet of Amazon EC2 instances. The application reads messages from an Amazon Simple Queue Service (Amazon SQS) queue and processes the messages in parallel. The message volume is unpredictable and highly variable.

The company must ensure that the application continually processes messages without any downtime.

Which solution will meet these requirements MOST cost-effectively?

A
Use only Spot Instances to handle the maximum capacity required.
B
Use only Reserved Instances to handle the maximum capacity required.
C
Use Reserved Instances to handle the baseline capacity. Use Spot Instances to provide additional capacity when required.
D
Use Reserved Instances in an EC2 Auto Scaling group to handle the minimum capacity. Configure an auto scaling policy that is based on the SQS queue backlog.