What does a Sally port prevent?

A Sally port is specifically designed as a secure entry and exit system for correctional facilities, acting as a double-door mechanism that prevents unauthorized access. This design allows only one door to be open at a time, ensuring that individuals cannot enter or exit the facility without going through a controlled process. By maintaining this controlled environment, a Sally port significantly enhances security by mitigating the risk of breaches that could lead to escapes or unauthorized entry.

The nature of the Sally port means it is particularly effective at ensuring that only authorized personnel and processes are allowed through, thus reinforcing the overall safety and integrity of the facility. While the other options address important aspects of correctional security, the primary function of the Sally port is to regulate access and prevent unauthorized individuals from entering the facility, making that the most fitting answer.