If you are unsure about someone's access to classified information, what should you do?

When you are uncertain about someone's access to classified information, it is crucial to notify your supervisor. This action is appropriate because supervisors are typically responsible for ensuring that sensitive information is handled correctly and securely. They are trained to assess the situation and take appropriate steps, which may include determining if there has been a breach of protocol or if further investigation is warranted.

Bringing your concerns to a supervisor allows for a controlled and official response, ensuring that the matter is addressed in accordance with established policies and procedures regarding classified information. This approach also protects the integrity of the information and helps maintain a secure working environment.

The other options do not appropriately address the seriousness of the situation. Ignoring concerns can lead to security vulnerabilities, investigating the matter yourself may compromise the inquiry or lead to misunderstandings, and discussing it informally with colleagues could spread information unnecessarily and potentially create a tense work environment without resolving the issue. Therefore, notifying your supervisor is the most responsible and effective course of action.