This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory System Pa 3, Subject name: Physiology
[{'content': 'Least (A-V )O2 difference is seen in \nSelect and explain. \nA. Hypoxic hypoxia, B. Anemic hypoxia, C. Stagnant hypoxia, D. Histotoxic hypoxia', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Histotoxic hypoxia Cause Decreased ability of cell to use O2 Examples Cyanide poisoning PaO2 Normal Hb content Normal Aerial O2 content or %O2 saturation Normal A-V PO2 difference Decreased Peripheral chemoreceptor stimulation Present (toxin prevents chemoreceptor to use oxygen) Cyanosis Present', 'role': 'assistant'}]