You have a set of encryption keys that you manage in Cloud KMS. You're concerned about the possibility of the keys being deleted, either accidentally or maliciously. What feature should you enable to protect against this?

*Explanation:* Key Material Export Restrictions. A. Incorrect, versioning does not protect against deletion. B. Incorrect, rotation renews keys but doesn't protect against deletion. C. Incorrect, scheduled destruction would make the risk even higher. D) Incorrect, Import/Export does not offer protection against deletion. E) Correct, by setting export restrictions, you can ensure that even administrators cannot delete keys without going through a rigorous process, thus offering better protection against accidental or malicious deletions.