Which of the following is an administrative sanction?

An administrative sanction refers to a disciplinary action taken within an organization, primarily for violations of policies or regulations. The nature of the sanction is generally corrective and procedural rather than punitive in a criminal sense.

The revocation of security eligibility is considered an administrative sanction because it directly impacts an individual's access to classified information or areas, depending on their clearance level. Such a revocation typically arises from an assessment of an individual's behavior or actions in relation to security policies, signifying a formal administrative decision that affects the person's standing within the organization.

In contrast, while other options like demotion, written warning, and suspension of training privileges can also be disciplinary actions, they often pertain to performance and conduct evaluations rather than specifically addressing security clearance or access issues. Each of these may serve different purposes and may not necessarily align with the structured processes pertaining to security eligibility. Thus, revocation of security eligibility is distinct in its administrative context concerning information security and clearances.