An audit reported has identifies a weakness that could allow unauthorized personnel access to the facility at its main entrance and from there gain access to the network. Which of the following…

A Faraday cage blocks electromagnetic signals to prevent wireless eavesdropping or EMP attacks, but does not control or restrict physical personnel entry into a facility.

An air gap is a network security measure that physically isolates a network from unsecured networks, addressing network-level separation but not controlling who can physically enter the building.

A mantrap is a physical security control consisting of a small enclosed space with two interlocking doors, where the first door must close before the second opens, ensuring only authenticated individuals gain entry. This prevents tailgating and piggybacking, which are the most common ways unauthorized personnel exploit unsecured main entrances. By forcing single-person, verified entry, it directly resolves the vulnerability of unauthorized facility and subsequent network access.

Bollards are reinforced posts designed to prevent vehicle-based attacks or ram-raiding, and do not address the vulnerability of unauthorized individuals walking through an entrance.