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
Which of the following is the earliest clinical sign of Vit A deficiency? 
Select and explain. 
A. Bitot's spot, B. Corneal xerosis, C. Conjunctival xerosis, D. Keratomalacia
C: Conjunctival xerosis
Answer: C: Conjunctival xerosis 
Explanation: The ocular manifestation of Vit A deficiency includes night blindness, conjunctival xerosis, Bitot's spot, corneal xerosis and keratomalacia. Extra ocular manifestation of Vit A deficiency includes follicular hyperkeratosis, anorexia and growth retardation. Ref: Park, 21st Edition, Page 568.