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': 'The organism which can invade the intact corneal epithelium and produce purulent corneal ulcer is: \nSelect and explain. \nA. Neisseria meningitidis, B. Pseudomonas pyocyanea, C. Pneumococcus, D. Streptococcus haemolyticus', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. Neisseria meningitidis', 'role': 'assistant'}]