Correct Answer: C

Enabling autoscaling ensures that the instance group can dynamically adjust the number of instances based on incoming traffic. By setting both the minimum and maximum number of instances to 1, you guarantee that only a single instance will be active in the project. This setup also ensures that if the VM crashes due to any underlying hardware failure, another instance will be automatically added to maintain availability.

Why not the others?

• A: Incorrect because setting the maximum number of instances to 2 could allow more than one instance to be active, which is not desired.
• B: Incorrect because disabling autoscaling means no new VM will be created to replace a crashed instance, failing to meet the requirement of having the application running at all times.
• D: Incorrect for the same reasons as A and B combined; it disables autoscaling and allows for more than one instance, contradicting the requirement.

For more information, refer to the Google Cloud documentation on autoscaling.