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': 'Gumma occurs in: \nSelect and explain. \nA. Primary stage of Syphilis, B. Secondary stage of Syphilis, C. Tertiary stage of Syphilis, D. Primary tuberculosis', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]