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': 'Hypopyon ulcer may be produced by: \nSelect and explain. \nA. Pneumococcus, B. Pseudomonas, C. Gonococcus, D. All of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans.All of the above', 'role': 'assistant'}]