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
[{'content': 'The definitive colour of the iris depends upon the: \nSelect and explain. \nA. Anterior limiting layer, B. Stroma, C. Anterior pigmented epithelium, D. Posterior pigmented epithelium', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. Anterior limiting layer', 'role': 'assistant'}]