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: Microbiology
[{'content': 'Causative organism of which STD has safety pin appearance: \nSelect and explain. \nA. LGV, B. Chancroid, C. Syphilis, D. Herpes genitalis', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is. 'c' i. e., Chancroid", 'role': 'assistant'}]