You want to use API tokens and other secrets within your team's Terraform workspaces.

Rationale for Correct Answer:

C: Securely managed .tfvars files are acceptable if not committed to version control.

D: HCP Terraform provides secure storage for sensitive variables.

E: HashiCorp Vault is designed for secrets management and integrates with Terraform.

Analysis of Incorrect Options (Distractors):

A: Plaintext storage is insecure.

B: Secrets should never be committed to version control.

Key Concept:Sensitive values must be stored using secure secret management solutions.