This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Medicine
What term is used to describe this finding? 
Select and explain. 
A. Arc eye, B. Asthenopia, C. Choroideremia, D. Coloboma
D: Coloboma
Answer: D: Coloboma 
Explanation: Answer D. ColobomaColobomas are the result of abnormal closure of the optic fissure. They may occur anywhere along the optic fissure and can affect the iris, choroid, or macula. Isolated iris colobomas are asymptomatic, but those involving the macula or the optic disk can result in severe visual impairment. Typical iris colobomas occur in the inferonasal quadrant.