What action should firefighters take when confronted with an exposed building that has a sprinkler system?

When firefighters encounter an exposed building equipped with a sprinkler system, connecting and charging the sprinkler system is the appropriate course of action. This step ensures that the existing fire protection mechanism is operational, which can help control the spread of fire and minimize damage to the structure and contents.

By connecting and charging the sprinkler system, firefighters leverage the built-in firefighting capability of the system, allowing it to function optimally alongside their efforts. This can lead to a more effective firefighting strategy, as the sprinkler system can help to suppress the fire until it can be fully extinguished.

The other options suggest actions that undermine the sprinkler system's effectiveness. Ignoring the system overlooks a vital tool in fire suppression. Disconnecting it can lead to unnecessary water damage and loss of essential fire control capabilities. Sealing off the system also prevents it from functioning, which is counterproductive when immediate suppression is needed. Therefore, connecting and charging the sprinkler system plays a crucial role in ensuring firefighter safety and protecting property during firefighting operations.