A bank uses a wireless network to transmit credit card purchases to a billing system. Which of the following would be MOST appropriate to protect credit card information from being accessed by…

An air gap involves physically isolating a network from all other networks, which provides extreme security by preventing any data transfer in or out, but it does not directly address containing wireless transmissions within a specific physical boundary for an active wireless network that needs to transmit data.

Infrared detection is a physical security measure primarily used to detect motion or intrusion based on heat signatures, and it does not block or contain wireless data transmissions.

A Faraday cage is an enclosure that blocks electromagnetic fields, effectively preventing wireless signals from propagating outside a defined physical space. By installing a Faraday cage around the area where credit card data is transmitted wirelessly, the radio frequency (RF) signals are contained, preventing unauthorized individuals outside the premises from intercepting them.

Protected distributions, often associated with TEMPEST standards, relate to preventing compromising emanations from equipment or cabling, but a Faraday cage is a more direct and effective solution for containing intended wireless transmissions within a specific area.