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
Congenital anomalies of optic disc include all except? 
Select and explain. 
A. Coloboma, B. Drusen, C. Hypoplasia, D. Opaque nerve fibres
D: Opaque nerve fibres
Answer: D: Opaque nerve fibres 
Explanation: Medullated nerve fibres / opaque nerve fibres represent myelination of nerve fibre of retina.