Which system utilizes mechanical or electrical parts for fire protection?

The active fire protection system is characterized by its reliance on mechanical or electrical components to initiate protection measures in the event of a fire. This system actively engages in fire suppression through various mechanisms, such as sprinklers, alarms, fire extinguishing systems, and other automated devices. These components work together to detect or extinguish fires automatically or assist in the manual response to a fire incident.

In contrast, a passive fire protection system is designed to contain fires and slow their spread without any action being taken. It relies on the structural elements of the building, such as fire-resistive walls and floors, to achieve this containment. Meanwhile, a visual alarm system primarily focuses on alerting individuals to a fire rather than actively suppressing it. An environmental control system pertains to the broader management of the living environment within a building, often focusing on heating, ventilation, and air conditioning, rather than fire protection specifically.

Thus, the essential characteristic of the active fire protection system is its use of mechanical or electrical devices to provide a direct response to fire, which is why it is the correct choice in this context.