This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cornea and sclera, Subject name: Ophthalmology
[{'content': 'Organism not invading intact cornea - \nSelect and explain. \nA. Gonococci, B. C. diphtheriae, C. Meningococci, D. Pseudomonas', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Following three pathogens can invade the intact corneal epithelium and produce ulceration:Neisseria gonorrhoea,corynebacterium diphtheriae and Neisseria meningitidis. Reference:Comprehensive Ophthalmology,AK Khurana,6th edition,pg no.99', 'role': 'assistant'}]