You are using Terraform to manage infrastructure as code within a CI/CD pipeline. You notice that multiple copies of the entire infrastructure stack exist in your Google Cloud project, and a new copy is created each time a change to the existing infrastructure is made. You need to optimize your cloud spend by ensuring that only a single instance of your infrastructure stack exists at a time. You want to follow Google-recommended practices. What should you do?

A. Create a new pipeline to delete old infrastructure stacks when they are no longer needed. B. Confirm that the pipeline is storing and retrieving the terraform.tfstate file from Cloud Storage with the Terraform gcs backend. C. Verify that the pipeline is storing and retrieving the terraform.tfstate file from a source control. D. Update the pipeline to remove any existing infrastructure before you apply the latest configuration.