This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory System, Subject name: Physiology
Peripheral chemoreceptors are stimulated maximally by: 
Select and explain. 
A. Cyanide, B. Anemia, C. Hypocapnia, D. Alkalosis
A: Cyanide
Answer: A: Cyanide 
Explanation: Ans. A. Cyanidea. "Carotid and aortic bodies can also be strongly stimulated by certain chemicals,b. particularly cyanide ion and other poisons of the metabolic respiratory chain." Cyanide produces histotoxic hypoxia of glomus cell. Hypoxia leads to closure of O2 sensitive K+ channel of glomus cell and stimulation.