Final answer:
The true statement is that public officials cannot recover damages for defamatory falsehoods unless they prove the statement was made with 'actual malice.' Knowing, willful, or negligent disclosure of classified information is not the only sanctionable behavior; others include defamation under specific standards, unauthorized access, inadequate security, and failure to report breaches.
Step-by-step explanation:
The statement regarding the constitutional guarantees for public officials concerning defamation is true. The United States Supreme Court established in New York Times Co. v. Sullivan (1964) that to protect the free flow of ideas and opinions on public issues, there is a legal standard known as "actual malice" that must be met for public officials to win a defamation lawsuit. This standard requires that the public official prove the statement in question was made with knowledge of its falsity or with reckless disregard for whether it was true or false.
Therefore, when it comes to individual sanctions, knowing, willful, or negligent disclosure of properly classified information is not the only behavior that can lead to them. Sanctions may also arise from other behaviors such as defamation, given the outlined standard of "actual malice." Amongst others, unauthorized access to sensitive information, not maintaining adequate security measures, and failing to report security breaches promptly can also lead to individual sanctions.