Final answer:
Oxygen is not produced in fires; it is actually consumed during the combustion process. Instead, gases like carbon monoxide, carbon dioxide, and, in some cases, hydrogen chloride are produced.
Step-by-step explanation:
The gas that is not produced in fires is oxygen (D). During a fire, substances undergo combustion reactions in the presence of oxygen, and the products usually include gases like carbon monoxide (CO) and carbon dioxide (CO2). Gases such as hydrogen chloride (HCl) can also be produced if chlorine-containing substances are involved in the fire. However, oxygen is consumed in the combustion process and is therefore not produced by the fire itself, making it the correct answer to the question.