Which of the following systems requires the presence of fire before activation?

A Pre-Action System is designed to require the presence of a fire before activation, embodying a two-step process. This system uses both a detection mechanism and a sprinkler system; it is essentially a combination of a fire detection system and a fire sprinkler system. In this setup, the fire detection system must first identify a fire and initiate the pre-action valve to open, allowing water to fill the pipes. Then, once a sprinkler head is activated due to the heat from the fire, water is released for suppression.

This design offers a layer of protection against inadvertent water discharge, making it suitable for areas where accidental water damage could be costly or catastrophic, such as museums and data centers. In contrast, systems like Wet and Dry Pipe Systems release water automatically when certain predetermined conditions are met, regardless of detection, while the "None of the above" option does not accurately represent any functional fire suppression system's requirements.