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
In xerophthalmia classification X 2 stage is ? 
Select and explain. 
A. Bitots spots, B. Corneal xerosis, C. Corneal ulceration, D. Corneal scar
A: Bitots spots
Answer: A: Bitots spots 
Explanation: Ans. is b i.e., Corneal xerosis WHO classification (1982) The new xerophthalmia classification (modification of original 1976 classification) is as follows : XN Night blindness X1A Conjunctival xerosis X1B Bitot's spots X2 Corneal xerosis X3A Corneal ulceration/keratomalacia affecting less than one-third corneal surface. X3B Corneal ulceration/keratomalacia affecting more than one-third corneal surface. XS Corneal scar due to xerophthalmia XF Xerophthalmic fundus.