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: Pathology
[{'content': 'Anti U1 RNP is a feature of: \nSelect and explain. \nA. SLE, B. MCTD, C. Sclerorema, D. CREST', 'role': 'user'}, {'content': 'Answer: B \nExplanation: MCTD', 'role': 'assistant'}]