The statement that best describes the concept of immutable infrastructure in the context of automation is:

A. It is the practice of deploying a new server for every configuration change.

Immutable Infrastructure Concept: This approach to infrastructure management involves replacing servers or components entirely rather than making changes to existing configurations once they are deployed. When a change is needed, a new server instance is provisioned with the desired configuration and the old one is decommissioned after the new one is successfully deployed and tested.

Benefits: Immutable infrastructure minimizes the risks associated with in-place updates, such as inconsistencies or failures due to configuration drift. It enhances reliability and predictability by ensuring that the deployed environment matches exactly what was tested in staging. This practice is particularly aligned with modern deployment strategies like blue/green or canary deployments.

References: The concept of immutable infrastructure is widely discussed in DevOps and cloud computing literature as a method to increase consistency and fault tolerance in automated environments.