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: Ophthalmology
[{'content': 'Conjunctival ulceration may suggest: \nSelect and explain. \nA. Embedded foreign body, B. Tuberculosis, C. Syphillis, D. Syphillis', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. Syphillis', 'role': 'assistant'}]