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': 'Characteristic pathological feature of rheumatic fever is/are: \nSelect and explain. \nA. Joint pains, B. Fever, C. Aschoff modules, D. All of the above', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]