This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S, Subject name: Pathology
[{'content': 'Me Callum patch is seen:(1991) \nSelect and explain. \nA. Rheumatoid arthritis, B. SLE, C. Rheumatic fever, D. Polyarthritis nodosa', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans: c (Rheumatic fever)Ref: Robbin's, 7th ed, p. 594 & 6th ed, p. 572", 'role': 'assistant'}]