According to NFPA 13, what is the minimum required number of sprinklers that must be operational during a fire?

The correct choice indicates that at least one sprinkler must be operational during a fire. This requirement is based on the understanding that even a single operational sprinkler can make a significant difference in controlling or extinguishing a fire, thereby helping to protect lives and property. The design and function of fire suppression systems, as outlined in NFPA 13, emphasize the importance of ensuring that at least one sprinkler is reliably available to activate in the event of a fire.

While having more than one sprinkler operational can enhance the effectiveness of the fire suppression system and are generally recommended for comprehensive fire protection, the code sets a minimum standard that recognizes the critical role of even a single sprinkler in providing an early response to fire conditions. This foundational requirement ensures that facilities will have some level of fire protection, which is crucial for effective fire management and safety.