The correct answer is C. Carbon Dioxide.
Carbon dioxide is a gas that is heavier than air. It can be used to extinguish fires by displacing the oxygen in the air, which is necessary for combustion. Carbon dioxide is also non-flammable and non-toxic, making it a safe and effective fire extinguishing agent.
Hydrogen is a gas that is lighter than air. It is highly flammable and can easily ignite, making it a dangerous fire extinguishing agent.
Carbon monoxide is a gas that is poisonous and can be fatal if inhaled. It is not effective at extinguishing fires.
Marsh gas is a gas that is produced by the decomposition of organic matter in swamps and marshes. It is flammable and can easily ignite, making it a dangerous fire extinguishing agent.
In addition to carbon dioxide, other common fire extinguishing agents include water, foam, and dry chemical. Water is effective at extinguishing fires by cooling the fuel and by smothering the fire. Foam is effective at extinguishing fires by forming a barrier between the fuel and the oxygen in the air. Dry chemical is effective at extinguishing fires by interrupting the chemical reaction that is necessary for combustion.