Which of the following actions are forbidden when the Terraform state file is locked? (Choose three)

When the Terraform state file is locked, it ensures that the state file is not modified concurrently by multiple processes, which could lead to race conditions or corruption. Actions that modify the state or require it to be read and potentially altered cannot be performed while the lock is in place.

In this context, the action of creating a plan, applying changes, and destroying infrastructure all involve reading from or writing to the state file and therefore cannot proceed while the state file is locked. Terraform prevents the execution of these actions to maintain the integrity of the state.

On the other hand, validating configurations does not require access to the state file because it only checks the syntax and structure of the Terraform configuration files without interacting with the current state. Hence, this action could still be executed even if the state file is locked.

This understanding reflects the operational safeguards built into Terraform to protect the state management lifecycle.