This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nutrition and health, Subject name: Social & Preventive Medicine
The earliest clinical sign of vitamin A deficiency is - 
Select and explain. 
A. Conjunctival xerosis, B. Corneal xerosis, C. Bitots spots, D. Keratomalacia
A: Conjunctival xerosis
Answer: A: Conjunctival xerosis 
Explanation: Conjuctival xerosis is the early manifestation of vitamin A deficiency. REF. PARK'S TEXTBOOK OF PREVENTIVE AND SOCIAL MEDICAL 21ST EDITION. PAGE NO - 568