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: Medicine
[{'content': 'Which is not a major component of rheumatic fever? \nSelect and explain. \nA. carditis, B. polyarthritis, C. sub cutaneous nodules, D. arthralgia', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]