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
Keratomalacia is - 
Select and explain. 
A. Occurs due to Vit-A deficiency, B. Relatively benign condition, C. First feature of Vit- A deficiency, D. Also seen in retinitis pigmentosa
A: Occurs due to Vit-A deficiency
Answer: A: Occurs due to Vit-A deficiency 
Explanation: Keratomalacia is due to deficiency of vitamin A.
It is not relatively benign. Larger stromal defects in keratomalacia commonly result in blindness.
Earliest symptom is nightblindness and earliest sign is conjunctival xerosis.
Retinitis pigmentosa does not cause keratomalacia.