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
[{'content': 'First clinical sign of Vitamin-A deficiency is \nSelect and explain. \nA. Night blindness, B. Conjunctival xerosis, C. Bitot’s spots, D. Keratomalacia', 'role': 'user'}, {'content': "Answer: A \nExplanation: All the ocular manifestations of Vitamin-A deficiency are collectively known as 'Xerophthalmia' (Dry Eye) –\nXerophthalmia is most common in children aged 1 - 3 years\n\n'First clinical sign' of Vitamin-A deficiency: Conjunctival xerosis\n'First clinical symptom' of Vitamin-A deficiency: Night blindness\nConjunctival xerosis in Xerophthalmia has a characteristic appearance of 'emerging like sand banks at receding tide\n'Bitot's Spots' are triangular, pearly-white or yellowish, foamy spots on bulbar conjunctiva, on either side of cornea; In young children they indicate Vitamin-A deficiency, whereas in adults they are often inactive sequelae of earlier disease", 'role': 'assistant'}]