This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
[{'content': 'If a patient with Raynaud’s disease immersed his hand in cold water, the hand will \nSelect and explain. \nA. Become red, B. Remain unchanged, C. Turn white, D. Become blue', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]