This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General physiology, Subject name: Physiology
[{'content': 'Hypoxia causes vasoconstriction in \nSelect and explain. \nA. Muscle, B. Lungs, C. Liver, D. Spleen', 'role': 'user'}, {'content': 'Answer: B \nExplanation: "O2 deficiency (Hypoxia), Accumulation of CO2,| PH produce vasoconstriction in the lungs. While these in the other tissues produce vasodilatation.Ref: Guyton; 13th edition', 'role': 'assistant'}]