Which two fire-fighting agents are used in the twin agent units on board flight and hangar deck mobile fire-fighting equipment?

The correct answer is B, AFFF/Halon 1211, as both of these agents are commonly utilized in the twin agent units found in the mobile fire-fighting equipment on board aircraft carriers and other naval vessels.

AFFF, or Alcohol-Resistant Aqueous Film-Forming Foam, is an effective fire-fighting agent designed to combat flammable liquid fires, such as those involving aviation fuel. It works by forming a blanket of foam over the flammable liquid surface, preventing the release of flammable vapors and smothering the fire.

Halon 1211 is a brominated fire-extinguishing agent that is effective for a wide range of fires, particularly electrical fires and fires involving flammable liquids. It disrupts the chemical reactions occurring in the fire, effectively extinguishing the flames.

Combining these two agents maximizes the effectiveness of fire-fighting efforts on the flight deck and within hangars, where aircraft operations pose unique fire hazards. The use of both AFFF and Halon 1211 allows for a versatile response to various fire situations that may arise.

The other options, while they may involve various fire-fighting agents, do not represent the specific combination used in twin agent units as dictated by naval fire