This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Eye, Nose and Ear, Subject name: Anatomy
[{'content': 'Failure of the choroid fissure to close results in \nSelect and explain. \nA. Congenital detached retina, B. Congenital aniridia, C. Congenital aphakia, D. Coloboma iridis', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Failure of the choroid (optic) fissure to close results in a cleft of the iris--called coloboma iridis (mostly in inferonasal position). This defect may extend into the ciliary body, choroid, optic nerve, or retina. Congenital aphakia--absence of the lens--may result from defective development of the lens placode.', 'role': 'assistant'}]