Which feature helps in managing sensitive data in Terraform?

The feature that helps in managing sensitive data in Terraform is the use of Terraform variables. Specifically, Terraform allows you to define input variables that can be marked as sensitive. Using these sensitive variables ensures that no sensitive data, such as secrets, passwords, or API keys, is displayed in plain text in Terraform outputs or logs.

When a variable is defined with the "sensitive" attribute set to true, Terraform hides its value in the CLI output, thereby providing a layer of security by protecting sensitive information during execution. This practice is vital in maintaining the confidentiality of data that should not be disclosed in your infrastructure as code workflow.

While the other options may serve important roles in Terraform's functionality, they do not specifically address the management of sensitive data in the same direct way. For instance, the backend handles the state file management but does not specifically focus on sensitive data. Workspaces help manage different states within the same configuration but don't inherently protect sensitive information. Additionally, there is no dedicated "Terraform secrets manager" within Terraform; sensitive data management is primarily achieved through the use of sensitive variables.