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
Which of the following organism can penetrate the normal cornea –a) Gonococcusb)  Pseudomonasc) Diphtheriad) Streptococcuse) Staphylococcus epidermidis 
Select and explain. 
A. a, B. bc, C. ad, D. ac
D: ac
Answer: D: ac 
Explanation: The organisms which can penetrate intact corneal epithelium are Neisseria gonorrhoea, Haemophilus Aegyptus, Corynebacterium diphtheriae, Listeria species and Neisseria meningitides.