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': 'Secondary syphilis occurs after \nSelect and explain. \nA. 6 weeks, B. 9 weeks, C. 13 weeks, D. 1 week', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]