This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Neuro-Ophthalmology, Subject name: Ophthalmology
[{'content': 'Lamina cribrosa is absent in: \nSelect and explain. \nA. Morning Glory syndrome, B. Nanophthalmia, C. Colobama of retina, D. Optic nerve agenesis', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. (a) Morning Glory syndromeRef: Morning Glory syndrome- A histopathological study British Journal of ophthalmology; the morning Glory syndrome' Opthalmologica 1983; 187 (7): 222-230 1990, 74; 56-58", 'role': 'assistant'}]