This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Circulation: Circulatory Shock and Its Treatment, Subject name: Physiology
[{'content': 'Shock causes: \nSelect and explain. \nA. Stagnant hypoxia, B. Anemic hypoxia, C. Hypoxic hypoxia, D. Histotoxic hypoxia', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans: A (Stagnant hypoxia)Ref: Pat GK, Hypoxia and Oxygen Therapy, In: Textbook of Medical Physiology, 2nd ed, Abuja Publishing House 2011: 94: 754-55Explanation:Refer the explanation of previous question', 'role': 'assistant'}]