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
Stem cells are present where in cornea? 
Select and explain. 
A. Limbus, B. Stroma, C. Epithelium, D. Descmet's membrane
A: Limbus
Answer: A: Limbus 
Explanation: Limbal stem cells (also c/d corneal epithelial stem cells) are stem cells located in the basal epithelial layer of the corneal limbus.