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
Xerosis/ Xerophthalmia is due to deficiency of: March 2013 (h) 
Select and explain. 
A. Vitamin K, B. Vitamin E, C. Vitamin D, D. Vitamin A
D: Vitamin A
Answer: D: Vitamin A 
Explanation: Ans. D i.e. Vitamin A