Which of the following is an example of a security technology used in facilities?

Burglar alarm systems are specifically designed to detect unauthorized entry into a facility, making them a clear example of security technology. These systems include sensors, alarms, and monitoring systems that activate when a breach occurs, effectively providing a layer of protection to the premises and its occupants. Their primary function is to deter theft and provide alerts to security personnel or law enforcement, thereby enhancing the overall security of a facility.

In contrast, the other options, while important for overall facility operations, do not pertain specifically to security. Water sprinklers are used for fire suppression, elevator systems are focused on building accessibility and transport, and heating, ventilation, and air conditioning systems (HVAC) are essential for climate control. These systems contribute to the safety and comfort of a facility but are not designed primarily for security purposes. Therefore, burglar alarm systems stand out as the appropriate example of security technology in this context.