Which security system prevents sharing an entry card with someone behind you?

• A. Anti-Passback System
• B. Administrator
• C. AdHoc
• D. ActiveX

Answer: (A)

This item is about anti-passback in access control, which binds a credential to a single person and a single access session so it can’t be used by someone else after it’s been used. In practice, when you swipe to enter, the system marks that card as having an active session inside that area. Until that session is ended—typically by exiting or revalidating at the proper reader—the same card cannot be used again to grant entry for a different person. This prevents the scenario where someone behind you borrows your entry card to slip in, because the system won’t allow a second person to reuse the card until the first person has left and the session is cleared.

Administrator is just a role with privileges, not a mechanism to prevent card sharing. AdHoc isn’t a standard security feature for this purpose, and ActiveX is a software framework unrelated to physical access control.