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: Social & Preventive Medicine
First ocular sign of Vitamin A deficiency ? 
Select and explain. 
A. Bitot's spot, B. Conjunctival xerosis, C. Night blindness, D. Keratomalacia
B: Conjunctival xerosis
Answer: B: Conjunctival xerosis 
Explanation: Ans. is 'b' i.e., Conjunctival xerosis