Confirming to delete all the resources in Terraform will have the following impact:

D. It destroys all the resources in the state file.

Terraform State File Role: The terraform.tfstate file contains a real-time mapping of the resources that Terraform manages, including their current configuration and relationships. This file tracks the actual state of resources provisioned by Terraform.

Impact of Destruction: When Terraform prompts for confirmation to destroy resources, and 'yes' is entered, Terraform reads the state file and systematically removes all the resources that are managed as part of that state. This is not limited to a specific .tfvars file, IAM user, or resource group—it is a global action that affects all resources tracked by the state file associated with the current Terraform workspace and configuration.

References: The function of the terraform.tfstate file and the impact of resource destruction are detailed in Terraform's official documentation. This behavior is fundamental to how Terraform manages infrastructure as code.