Which of the following is a type of fire extinguisher commonly found on ships?

Foam extinguishers are commonly found on ships because they are effective at combating a variety of fires, particularly those involving flammable liquids, such as oils and fuels, which are prevalent in marine environments. These extinguishers work by creating a barrier between the fuel and the oxygen in the air, suppressing the fire while also preventing re-ignition. The versatility of foam extinguishers makes them suitable for use on the deck and in other areas where different types of combustible materials may be present.

In contrast, hydrogen extinguishers are not commonly used in firefighting since hydrogen is itself a highly flammable gas, making it unsuitable for extinguishing fires. Steam extinguishers also have limited application and are not standard on ships, as they require a significant amount of water and can be hazardous in confined spaces. Chlorine extinguishers are typically not used in firefighting scenarios because chlorine gas is toxic, and using it can pose significant health risks to personnel and damage equipment. Thus, foam extinguishers are the recognized standard for fire suppression on ships due to their effectiveness and safety.