Final answer:
Asphyxiants interfere with oxygen exchange during normal respiration.
Step-by-step explanation:
The correct answer is d) Asphyxiants. Asphyxiants are substances that interfere with normal respiration and prevent the exchange of oxygen. This can include gases like carbon monoxide and chemicals like cyanide, which inhibit oxygen delivery to bodily tissues and cellular respiration, leading to poisoning. Anesthetics, carcinogens, and irritants may have other effects on the body, but they do not specifically interfere with oxygen exchange during normal respiration.