Which of the following is considered an IaC file?

A Dockerfile qualifies as an Infrastructure as Code (IaC) file because it contains a set of instructions that automate the building, configuration, and deployment of a container image. This enables developers to define the environment and dependencies needed for an application, which can be version-controlled and processed consistently across different systems. The Dockerfile follows a declarative approach where the desired state of the application environment is specified in code.

Other choices do not align with the concept of IaC as clearly. Multiple virtual machine images represent a state of infrastructure rather than a coded definition of how to achieve that state. An XML file, while it can store data and configurations, does not inherently describe the infrastructure or automate its deployment in the same way that a Dockerfile does. Manual configuration relies on human intervention to set up infrastructure, which undermines the automation aspect central to Infrastructure as Code practices.