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
Organism not invading intact cornea - 
Select and explain. 
A. Gonococci, B. C. diphtheriae, C. Meningococci, D. Pseudomonas
D: Pseudomonas
Answer: D: Pseudomonas 
Explanation: 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