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
Hamarlopia is seen in 
Select and explain. 
A. Oguchi's disease, B. High myopia, C. Vitamin A deficiency, D. Congenital deficiency of cones
D: Congenital deficiency of cones
Answer: D: Congenital deficiency of cones 
Explanation: Hamarlopia (day blindness) is due to congenital deficiency of cones  and central corneal and central lenticular Opacities.