In the lavatory, which device is used to automatically extinguish a fire?

The correct choice highlights the use of a heat-sensitive capsule dispensing halon system in the lavatory for automatic fire extinguishing. This system is specifically designed to detect elevated temperatures indicative of a fire. When this heat is sensed, the capsule activates and releases halon, a fire suppression agent effective in controlling flames without causing substantial water damage or creating a mess.

Halon is particularly valuable in enclosed spaces like aircraft lavatories, as it rapidly suppresses fires while being less harmful to sensitive equipment and the environment compared to other agents. Its ability to work on various types of materials and its quick release mechanism make it suitable for emergencies where every second counts.

Other devices like fire blankets, water mist systems, and carbon dioxide extinguishers are commonly used in different contexts but do not provide the same automated response or efficiency in such a confined space. For example, fire blankets require manual deployment, water mist systems may not be as effective in a compact environment, and while carbon dioxide extinguishers can be useful, they also require manual use and may not be as effective against certain types of fires compared to halon.