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': 'Sequence of colour changes observed in Raynaud’s disease \nSelect and explain. \nA. Red, blue, white, B. White, blue, red, C. Blue, red, white, D. White, red, blue', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]